Bridesmaids dilemma!

Ok ladies so Im only having four bridesmaids & one of my bridesmaids recently told me that she couldn't walk with my brother because her boyfriend has a problem with it. Now all they had to do was walk side by side in church. I was only going to have a sweetheart table at the reception so anybody was free to sit where they liked. So I had to switch her partner which is fine, ok I did that. But before she told me the situation, Her boyfriend blew everything out of proportion stating that she was an embarrassment if she walked with someone other than another family member and other rude things. It got so bad that he left her apparently! Now I had already told her that I was gonna switch her partner but today she texted me again to reassure herself. I had also told her that if my wedding would cause her problems its okay if she no longer wanted to be in it, she said no that she still really wanted to. Like ok cool and that in the future she doesnt know if they will get back together con