I see no problem going on vacation with your daughter alone.
If you can afford both trips in one year, great!
If the problem is that you can't afford a vacation with her and then another one with DH, sit her down and tell her how important it is to have alone time with your spouse. That he deserves to have you one on one as much as she does, so you'll have to alternate vacations.

Get her involved in the planning and looking at costs. Hopefully she'll appreciate the money spent and will learn to save for the trips she'll still want to take but with her friends and not you in a few years.

Do the separate week just with her if you can afford it, but let her know the gravy train stops at some point. It is important to,let her know that she must become self supporting at a certain age, or you will be stuck with a failure to launch.

She does need to accept that you need time alone with your new spouse. This interim time before she leaves home is precious. My sons are in their 20's and family holidays are now a distant memory. Enjoy it while you have it.

The fact that kids get to on vacation with one parent, should be used as an excuse to exclude them from one with the other parent when that parent's STEPKIDS are included.

I don't understand the whole idea of trying to get a man or woman to play happy family with your bios while excluding his. Stepkids are not more deserving of a vacation with their stepmom/stepdad than the bio kids.

I mean you took them all on your family moon and I am inferring that you didn't get a honeymoon. I think this one is for you and DH. Explain it that way.

I am sorry but the day you got married was the day you decided that your DH will be above your children in certain ways.
You have to sit your daughter down and say yes - I am not single anymore, I'm married thus things will change, I'm the adult you are the child ... over and done with.

I was in the same situation with my BS, When I started dating SO he was not the happiest kid in the country, but I simply told him, This is my boyfriend and you are my kid, I love you both in different ways stop your brat attitude or you will be sorry. Deigma immediately stopped and changed his attitude.... Aergia (SD) was a different story, still trying to break us up.... She's failing.....

The point is both the children in my house hold where minors, there was no such thing as bio parent and kid private holiday, excluding the new husband/boyfriend/partner. The holidays were planned in such a way that the kids went with, but they had their own time and we had our own time, When the kids where pre-teens, they joined your groups on the beach etc and evening we where all together.... now Deigma is an adult and Aergia a teen, we still go together and stay in the same house, but every one is doing heir own thing, we only see each other breakfast time to find out who's doing what.... not the best holidays I admit, but know what, soon both kids will be gone then SO and I can do romantic cruises, week long camping trips etc...

The day you get married - life simply has to change to accommodate every one, and no child should be the ruler... stop the mummy daughter holidays.... change it to mummy daughter facials a Saturday after noon and tell DH he's free to go down to the pub and hang with his mates watching sports... or Sunday which ever day suits him.

Welcome to this forum.

If you want to take the trip with your daughter, why don't you call it a Sweet Sixteen trip or Quinceanera or Launch of High School. Just pick a milestone that fits best. This way no expectations are created and, above all, the trip is not tied to your getting married.

From the new spouse's/stepparent's point of view, the worst possible thing you can do is frame your husband as a negative that must be compensated for. That instantly creates an insider dyad between you and your daughter and an outsider status for your husband. Your daughter will be striving to stay in -- your husband will feel increasingly alienated.

Model a great marriage for your daughter which means do NOT create some kind of peer status between her and your husband. I think what set off a lot of people here was the idea that she must be given a trip with you because he got a trip with you. It sounds kind and motherly to you from your innocent standpoint but those of us who've lived it instantly see the dangerous subtext.

The child should never be given the message that her relationship to stepdad is sort of a sibling one, looking for things to be even-stevens. No. He is your spouse, an adult in his own home, rightly expecting a special relationship with the woman he married.

The kid can be reassured that all is right in the world if the adults -- mom -- maintains a secure, in-charge status with her. Do NOT let your kid think she's moved into or near the driver's seat because you feel worried you rocked her world. Change is inevitable, teach her to embrace it. Your husband is a good man who will make both your lives better. Teach her to appreciate that.

I think this is an excellent oppotunity for you to have a discussion with your DD about how you and your DH are going to build a life together and make each other and the marriage the priority for both of you. Be sure to be clear with your DD that she remains your top responsibility but that things are changing and she will have to adjust. If the right situatio arrises then you can do a mom/daughter trip. If not... oh well.

Good luck and enjoy your vacation with your DH. DD will adjust. Kids are flexible, they bounce.