I think it's absolutely reasonable for your friend to disagree with what you are doing. But regardless of that, she should be there to give you support. That's what friends do! We don't always agree, but no matter what we stand by them and love them and help them if things go pair shaped!
Maybe contact her and let her know that you understand her concerns and that you have thought about them too. But that you have done your research and are happy with your decision and feel that this fighting isn't helpful. Maybe also say that you would appreciate her support even though she doesn't agree with it as you can't imagine going through a major event in your life without her?
I hope everything goes well xo
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