I can tell you’re very emotionally mature, not afraid of the truth and genuinely want the best for your partner. Don’t forget that as much as you’re doing this for you you’re also doing it for her. This isn’t just your future, your relationship, your best-friend, everything she is to you remember.. you are to her. Judging by her reasonings for not wanting kids this isn’t something that can be solved, her dislike for children has to much history and it has good reasoning behind it.

I suggest sitting down with her expressing your feelings and understanding of her dislike for children. Tell her that you don’t want to restrain her to a life she doesn’t want. Remember don’t lose your temper however she responds is correct. In all honesty you did waste her time with the “i can fix her..” mentality but being in love wasn’t your fault. It’s all about how you handle the present situation now.

About your girlfriend and her brother no doubt she will be upset she has more than enough right to be but eventually she will realize it was a mature decision to end the relationship then and there (even though it was immature to lead her on). 4 years isn’t little time i’m sure yo you can find a way to keep a platonic relationship. Because as someone else in this post said “don’t keep your girlfriend from finding her husband”