I honestly have no idea why some people were being so harsh!! You honestly said nothing wrong, your feelings are completely valid in my mind.. maybe these other people are having a bad day or something, but regardless the rude comments were not needed or justified!! You are obviously going above and beyond helping your friend right now, and I doubt you are going around only being concerned about your wedding and not her pregnancy like other people suggested, again nothing you said implied that! I'm getting worked up about this whole situation for you!! So know that you have one random person on your side right now!

I think a nice lunch date or something with your friend is in order to clear everything up. Ask what she wants to do about everything and go from their. You haven't even said you wanted her to do anything, just to be their with you the day of and during the planning! Not spend money or do everything for you.. just to be a friend and be their for you. You never know what will happen when the babies born, but hopefully everything goes well and everyone is healthy.. I just don't see why she's wanting to bail on it already :( their are great dresses she can find for like $40 on sale, so not a lot of money so if she can't be in it it's not a huge waste and she can sell the dress. Maybe she won't be able to stand up long during the ceremony, give her the option to sit whenever she needs to right off the side or have a chair right their for her. Maybe even have her holding the baby.. Maybe she doesn't want the baby around a lot of people though. So lots to talk about and consider.

But again you aren't in the wrong at all. Don't let people make you feel bad for no reason.