@hungryowl I'm not sure that you actually understand what becoming, and then being, an adult actually means - even though you purport to be 42 years old. The most common and usual pattern of our lives as healthy human beings, is that from the time of conception we take an average of 38 weeks to turn from a fertilized ovum into a fully formed tiny human being (40 weeks if you count from your last period). Of course, and incredibly sadly, some of those embryos and foetuses won't become fully formed and healthy babies - and for a myriad of reasons.
The healthy growth of a new born baby that thankfully continues all the way through to their adulthood, often appears, in retrospect, to have flown by - even though I do remember those seemingly endless sleepless nights when my first one was a new born!
As children we change rapidly in the first few year's, then the older we get, the slower it takes for us to keep on growing. By the age of 25/26 years, most of us will have matured enough to actually be considered an adult. Very young adults often enjoy partying and getting drunk, but sometimes, some of them can still behave irresponsibley - more like a 13 or 14 year old - than a 30+ year old.
However, most healthy adults will start to be at least a little calmer by the time they reach their 30s, which is the age when many young adults will start to think about maybe buying or renting a house for themselves for the first time, and maybe about settling down with the person they love. Or, on the otherhand, as their age creeps from 30 to 40 years old - and they officially become middle-aged - they might realise that they don't actually want the responsibilities of maintaining a home, or to ever share their living accommodation with another adult! That is just as reasonable a choice as wanting the whole of the rest of their lives to involve creating, and being enmeshed with another adult, along with possibly 'growing' their own children!
Imo, the worst thing we can do is to take the settling down route, with another adult and yet still expect to act like a 21 year old, unless, after indepth conversations between the couple, they both want to continue with their preferred lifestyles, and therefore they decide to not have any children, as the two things do not belong together. Anyone choosing to live either on their own, or in a like minded relationship, needs to realise that anyone else in their lives must be allowed to back away if they no longer want to live like that.
So you @hungryowl, are well within your rights to stay living as you have been, if that is what gives you pleasure in your life, and as long as you don't try to coerce someone else into behaving like you. Your friend has changed and grown and become the sort of adult who embraces their responsibilities, one who no longer gets any pleasure from a more hedonistic lifestyle. She no longer needs or wants to get drunk, and all that that entails, so going on the sort of holiday that you still want to have no longer appeals to her.
If she hadn't given you all your money back, I would have thought that her behaviour towards you was quite shabby. But she has given you that money, and you can easily go on the holiday alone, or with a friend. I think it might actually be good for you to go on your own, and for you to spend some quality time with your own thoughts, and wishes for the future.
Lastly, please stop bullying your 'probably' ex-friend, she has every right to have whatever kind of relationship with her husband that she wants! You are being extremely unreasonable OP to think that she should listen to you rather than to her husband.