Seriously i need help...bm monster.

I wouldn't kick her out, but maybe have coffee with her and explain your intentions for texting your brother and apologize that it upset her. I'd try and focus on building up the relationship and hopefully chatting about the wedding will come naturally. Also, as PP said, she really isn't obligated to help with the wedding planning, and I imagine it's probably awkward for her to try and help if she doesn't know you very well.

I don't understand why she's getting incredibly defensive for saying you shouldn't have gone to your brother/her bf when you were trying to help. I think you should have a chat with her and be transparent. This is your wedding and you are trying to include her because she may be a part of the family in the future.

Sounds like she is frustrated about something going on in her life and is blowing up at you. Also, if she can't pay for the cruise I don't think you should pay for her (unless you really wanted to extend an olive branch), but instead find someone else who can take her spot. But, I wouldn't kick her out of the party if your brother is intending on marrying her because she will be joining the family and will remember you not including her for the rest of her life.

- This is why I usually advise against asking people to be in your wedding party in hopes of getting closer. It really should just be your already-closest friends. Weddings can be stressful, and not just for the bride/groom, so having a solid foundation with your bridesmaids is super key.

- A cruise, as a multi-person event, is a nightmare to organize. You typically need to be 100% sure of your head count way ahead of time, so people need to know immediately if they have the time and funds, and it's often difficult to get out of. Additionally, cruises don't allow for people to leave early or join halfway through, which is usually a solution for people who can't afford a whole trip/have schedule restrictions. I think you probably should have anticipated at least one or two issues with a four-day bachelorette party on a boat.

- Bridesmaids aren't obligated to help or to offer up their assistance with wedding planning. Movies/TV shows have made us believe that is not the case, but its on the couple getting married to plan their wedding (or whomever they hire, of course).

- You shouldn't have texted your brother about someone else's finances. I get that they're in a serious relationship, even likely to get engaged soon, but that was uncalled for/a bit of an invasion of her privacy.

- Her saying your text to your brother was "childish" is a strange comment, but I understand being non-too-happy about it.

- Kicking her out is an option, but you should definitely weigh the consequences of the ripple effect here. This seems like a minor thing at best--I've definitely heard some horror stories about people who absolutely deserved to be kicked out and cut off by the couple--but she's pretty intwined in your family and I'd really take that into consideration.

I would sit her down and have a conversation with her where you tell her pretty much everything you wrote down. You don't know her well but you know she's important to your brother so you asked her to be a bridesmaid because you wanted to get to know her better. That you wanted to do something fun that everyone could participate in and that's why you asked everyone what they thought of the cruise before booking it, because you didn't want to do anything that would put anyone out money wise. That you really want her to be included but cannot afford to pay for her spot, so you were looking into less expensive rooms so she could still be there but it wouldn't be as difficult for her to swing financially. That you reached out to your brother because you thought he might want to chip in so you could participate, and that you didn't realize asking him would upset her... and on and on. You can say that you expected all the bridesmaids to contribute in these different ways (like helping out with parts of the wedding), but perhaps you didn't really explain that to her in the beginning when you asked her, and you probably should have. If you take ownership for your own actions (whatever they may be) and suggest that her inclusion was with the best of intentions, she should be receptive. If she and your brother are likely to be married in the future you are probably going to have to have her in your life for a long time, so it makes sense to try to smooth things over rather than just kick her out of the wedding.

If she doesn't respond well to that and the drama continues, then I think its totally fine to tell her she doesn't need to participate in your wedding party. You don't need drama like that. I do think this is a situation that could be rectified though, assuming you are both coming from a good place and reasonable people.

Take your wedding out of it and respond how you would if there were an issue with your brother's GF. I'd suggest sitting down with her and clearing the air. You shouldn't have gone to her bf behind her back, and it sounds like whatever she said to you was a response - seeming over-response - to that. She shouldn't have told you that your brother doesn't have time to talk to you and that you need to go through her to speak to him. Have a calm conversation wherein you apologize for your part in the dust up, and be prepared to forgive, or at least set aside. But leave her participation in your wedding out of it, unless you're looking for a way to blow up your relationship with her and your brother for good.

I would have a conversation face to face and clear the air. I feel a cruise is a big ask for anyone when they are already spending money on a dress, shoes, taking time off from work, shower gifts, etc. She may have assumed you were paying. Or maybe she does want to spend he money that way. Either way, have a talk about it. Play nice-she might be your sin someday.