I have a 23 year old step daughter. She has lived with us since she was 5 and her biological mom is out of the picture. She is as much mine as any of the others. She got her BSN and has been working as an RN for two years, lives in her own apartment, totally independent, etc.
My husband and I also have an 11 year old and a four year old. Last year, we went to wdw. We got a big condo at Bonnet Creek And she paid for her own park admission and all was good---except I did hear a lot of, "I paid for my own ticket so we should do what I want now..." I guess she is immature in that way (we try to do what everyone wants, but with an age range that drastic they all have to be pretty good about being patient.)
Later in the summer we did a two night weekend trip to a beach town about four hours away because my three year old wanted to see the beach and we wanted to do a last little hurrah before school started again. We did not take the twenty three year old because she was working, she hates the sun and the water, and because we only got one hotel room. She was VERY offended, and as a matter of fact, six months later at my four year old's bday party this weekend, she told my close friend that we left her at home and vacationed without her. My friend gave me an earful about that, you can be sure.
I don't know what the answer is. I hate that she was offended but she had to work and honestly doesn't like the beach. Also, the hotel room was over $300 a night, and it really wasn't in our budget to add another room. Realistically, we would have just stayed home instead of adding that expense or trying to find a time to reschedule when she didn't work. This was planned spur of the moment.
That doesn't seem fair either, since my 23 year old has had many trips with us alone and with her 11 year old sister under her belt, and we decided to go really because the three year old was obsessed with the beach.
We have tried to add my oldest to the big trips but it's almost impossible to add her to every small little weekend jaunt we take, both on an expense level and a scheduling level.
What I am going to try next is a cruise. My husband and I will have a room with the two younger girls. I have told my oldest when we are going and told her she is welcome but will need to pay for her own stateroom and suggested she bring a friend. We would pay for excursions, expenses, Etc. I am hopeful this will work out bc although she will pay for her own room, she will be with a friend and be able to do what they want to on their own during the day---so she shouldn't be stuck with the little kids a day. She is single with a full time, professional job and was looking at booking a cruise on her own anyway, so it seemed fair to me, although I still don't feel 100% good about it. It is a struggle to decide what is fair/right and preserve everyone's feelings!