DH and wills that basically leaves most of each our money to our own kids.   In most cases, I doubt stepkids get any money from a stepparent. 

It really depends on how long you were with your DH, how the Adult Skids interacted with the grandparents and if the grandparents decided not to include the adult Skids for a reason. There might be more history with the grandparents and the skids that you are not aware from the past.

My DAH is leaving Leech(SD) $500 and a letter explaining why it so little.

I dont have bios. I stand to inherit a not unsubstantial amount one day. My plans are to use it to live comfortably but I will most likely leave whatever is left to dh if he survives me... or his daughters

Well, unless someone in my DH's family strikes oil or wins the lottery, that's not something I have to worry about.  But . . . if it were to happen, I think I'd look into the family history a little before making any decisions.  The skids had little relationship with their parent/your spouse.  Why not?  Did they have a relationship with their grandparents?  Presumably the grandparents left the money to the spouse knowing that s/he was remarried.  They could have left the money to the grandchildren, or set up a trust.  Generational transfer didn't seem to be a priority to them.   Ultimately, unless I felt that the grandparents did not intend the money to go to the skids, I'd probably leave them a good chunk of it, though.

Last I checked, whatever is mine is mine to decide whether I share it or not... and with whom.

If he left it to YOU, and didn't split it up between you and the kids, then so be it. He must have had his reasons.

Though, I'd consider that they may try to claim a portion....so I'd sit on it for a while...at least until you know you're not being taken to court.

DH was upset because I wanted the money divided in half: half to my kids and half to his kids. Which does mean mine get "more" because I have fewer to divide the $$ between. But that's just fate, and all my money, my "half", would have gone to just my children if I were not married.

On the other side, my dad had me and my step siblings evenly divided in his will until a year or two ago when he told me he is leaving it all to me. They didn't have a falling out but he changed it. I don't feel right about that since some of the money he has is because my step mother died and her estate went into his. I don't expect it to be a lot, but I am wondering if I can figure out a way to give them some of it (whatever is left) without going against his wishes/will.

The deceased spouse's Will answered this question. It is your money to do with as you choose.  Give it to the former Skids, fund a scholarship at a local university, donate it to charity, enjoy it.

Whatever you choose.

Though in the presented scenerio it is likely the Skids could contest the Will regarding their GP's estate and would have a better than even shot at recovering some portion of the deceased SO's inherritance from his parents.

Wills and estate distribution can be a skitchy thing. It can be worse in blended family marriages.

In this scenario it would be my money to do as I pleased with. I certainly wouldn't bequeath any to the stepkids but leave it all to my and DH's biological son together.

I'd put some in trust for skids and keep some for myself.  If it's a fortune, and they are decent skids, why would someone not leave it to them?

Personally, I wouldn't feel right not leaving some for my skids.  I get along with them well, and I know it's what my DH would want.  I'd either put it in a trust for them or leave equal amounts to my SS's and mine & DH's bio kids in my will.  I wouldn't feel right cutting them out of money that I'm sure was intended for them in some way.

My DH would NOT WANT his kids to have it so I would follow his wishes.

You no longer need anything. Funeral !  If you have somewhat of a decent relationship with SK.  As they were not back stabbing you ect.  I would let them have the money. 

Since the money went first to my spouse and then to me I would have considered it the responsibility of first the grandparent then my partner to dictate if they wanted any money to go to their children over anyone else.  This means two people had a chance before me to control the money. By the time it’s gotten to me I would consider it mine to do with as I wish.

Given the relationship you describe with the step children though I would give them part of it upfront. They are adults and it was their father who passed. This is assuming the amount is substantial and goes beyond basic needs to provide for the loss of my partners income. For example if I passed tomorrow my insurance would barely cover mandatory expenses for my partner to stabilize with the loss of my income.

But if I were stable I would attempt to give them both part of the amount left. After that they are on their own and whatever is left after my death can be passed on to whomever I decide.

The fact you’re thinking about this now makes me think you’re a good person and you’ll make the right choice for you.

A good friend of mine’s dad died suddenly 2 years after marrying. He left everything to his new wife who had verbally promised him she would leave it to his adult daughters when she dies. He had discussed this with my friend, who just let it go as she thought her dad would be around for many more years. She told the daughters soon after the funeral that they wouldn’t be getting it and she was leaving it to her son. I think that’s awful as it was my friends family home and a very new marriage.

On flip side, my mother in law married a man who already had 3 adult kids from 2 previous marriages. One of those kids was his SS. He also had my DH as his SS. They were married for 35 years until he passed away. In that time he gave hundreds of thousands to his children to help with university and buying homes and starting up businesses. Mother in law only met them a handful of times in all those years, and in the 15 years I’ve been part of the family I met his kids for the first time at his funeral. They never came to his birthdays, Christmas, or even to visit when he was dying. Mother in law said once he stopped giving them money on demand they stopped contacting him. So in his will he wrote everything remaining (the bills for his care towards the end ate away a lot of what was left) was to go to my mother in law. Within a month of him passing away, mother in law had each of the kids asking her for their inheritance. One of whom turned nasty and called her all kinds of names and threatened her. Funny thing is they assumed everything was their dads and in fact the house was inherited by my mother in law so nothing to do with their dad. She has a comfortable life now, and that’s what he wanted for her so she feels no guilt. 

Well my SD hardly ever speaks to us unless she wants us to buy her something, so I wouldn't leave her anything. In your situation, I might consider leaving some to the skids especially since it came from their grandparents. However, I agree with the others who stated the grandparents and/or the spouse should have made clear what they want done with the money in this situation and if they didn't, it is really yours to do whatever you please with.