Why are you getting emails from her school? I thought you completely disengaged from all the schooling stuff. While this seemed to go ok, why invite the problems that often happen when you become involved in her schooling?

As a former chronic procrastinating middle schooler, and early HS student,  I can say definatively that no one ever works as hard for an A as they do for an F.  The stress, investment in self delusion, avoidance, lies, dodging , etc, etc, etc, is exhausting and far more work than just doing the work and doing it to the best of your ability.

Let her flunk.  She is off the DH/CLove payroll either way when she turns 18.  She can go fight with FF for mommy TTs sofa.

Buh-by PS loser. (L)- on the forehead.  Oh, but wait. She rescued her grades all by herself before.... see how she manages to make that happen this time. Actually all by her lonesome.

Good riddance.

Though I know that this is heartbreaking for both you and DH.  The second time I ever saw my dad cry was when I finished HS.  I had two sophomore years.  I did graduate with honors.  The third time I saw him cry, was 11yrs affer HS graduation. When I finally completed my BS.  What I put my parents through, should have never happened. That is one of my very few regrets. They would say that I was not that bad.  I, think they have the rose colored selective memory that many parents have.

My SKid did not get the slack that I did. His mom and I did not tolerate from him what I put my parents through.  Or what my DW's three  younger sibs pulled.  DW was a HS honor student. Yes, she had a child at 16, but she was a rockstar student.  BIL1, BIL2, and SIL barely graduated. In fact, they all three barely got the project work due their Freshman year turned in the day before graduation in order to actually graduate.

SS, had our collective foot up his ass to the extent that he was scared shitless that he would be dumped at the homeless camp if he failed to graduate on time. So, he graduated on time and with honors.   That was followed by 8mos of being our beck and call chore boy before he reported for USAF BMT.  His mom and I are comforted that he had incredible leaders who are professionals at engaging young people to deliver effectively as members of a team, perform with professionalism, and hold themselves accountable.  Though failing to get out of bed, report to work on time, and deliver as ordered, can get them put in jail.  Where that same thing in a civilian job just gets them fired.  I perfer the get your head out of your ass or go to jail option that the military option holds over the heads of young people.

When the end comes, you can block anything from the HS.  No doubt those emails will not be missed.

Whether she fails or not is her problem tbh

Idk what the law is in your state but where I am, child support is paid until 18 or graduation of high school whichever is later. So if she turns 18 but fails to graduate, your husband might be on the hook for the rest of the year depending on your state. It sucks

Thankfully my steps are dumb and most have dropped out or did a quick graduation alternate program so the ones who turned 18 were officially off.

Hoping the best for you and your finances. 

She will fail at life just like in school so I wouldnt be bothered if I were you except for the small child support detail

 "hard to get the camera because the class shares it."

Excuses. Excuses. One camera for the whole class to use. Must be some special camera!
There's no sign up sheet so that everyone has a turn before the assignment is due?

Summer school on the horizon. Child support through summer. 
Does the school let them walk for graduation if they have to go to summer school? 
If the family does graduation parties, I'd tell her no party until she actually finishes.
 

Just remember in CA it’s until 18 or graduated, so if she’s going to take summer school even if she’s 18 he might be on the hook to pay until she graduates.  Maybe ask a lawyer for clarification on that. 

Unsubscribe to those emails. 

If I hear about SD13s grades, its only because I've caught wind of DH and SD13 arguing. Last time I heard DH ask "why are you failing math and not turning in assignments?" SD13 response: "Because she can't teach." LOL WTF, no you're just lazy. *eyeroll*

Not my place to tell DH though. Also, not a newsflash to him that's she is lazy, so it wouldn't change anything anyway. 

Yikes.

Call the school and take yourself off.... she only has a few months and there will be MORE emails.. You emailed the teacher....You can't control the urges. Control what YOU can control. 

You can want a plan.. but she is very likely to not give it to you.. and based on her past history.. following up is problematic right?

I think you need to disengage completely from this because....

No matter what you do.. she will either graduate.. or not.. on time.. and it will never be because of your help.. but any failure you will own a piece of because you caused her extra stress.. so that becomes part of the excuse of why she didn't get it done.

Your husband is a doofus of a parent.. he doesn't care.. or perhaps he is so lazy about it because you overfunctioned for him.. but when you look back.. your "help" has most often resulted in more stress for you.. and whatever happened with your SD.. when it went bad you got blamed.. went good.. no credit... and honestly, your SO doesn't seem to value education.. or think it's that important to promote.. so YOU CANNOT CARE MORE THAN THE PARENT.

You also reallize that the reality is that your SD will be in your house after 18 if she wants to do that.. your SO won't cut her off.. she may choose to stay with mom.. but only to the point where mom or sister make that too toxic then she will boomerang back to dad's... and I dare say you have about zero say in that.. your SO won't stick to your boundaries.. when push comes to shove? his kid will be in his home.

I also get that you are extremely cheesed off at your SD.  She has been unnappreciative.. She has shown that she is not mature.. and that she will procrastinate.. and she will embarass you when you go out of your way to help her with opportunities.. the fact that you stick your neck out does not make her any  more interested in truly following through. She has also shown herself to be disloyal.. which when it comes to saving her own skin.. she saves it.. and throws you under the bus.. with dad.. with mom.  

The end result is that you aren't disengaged.. you DO care.. you actually seem to enjoy the fact that she has struggles.. and relish future failure.. whether that will happen or not.  That isn't disengagement.. 

You also have to realize that a lot of the hurt you have experienced has been because you put yourself out there.. and over and over again allowed others to take advantage.. I'm not saying you had to be a jerk.. but you have given them plenty of rope to hang you multiple times.

You probably would do well to make peace with the reality you have to face.. and become uninterested in her outcomes.. that is the disengagement.. not when you find it funny when she fails.. that you don't care.. because only she can impact the outcome.. and your SO won't protect your boundaries.. so if you stay.. that is what you have to accept.. and move on without letting it bother you.

I would almost suggest getting off this site.. stop posting because I think it keeps you  focused on your problems with her.. vs just ignoring her and her issues to the extent possible.