Sorry in advance for the long post! I’m sorry to hear you’re in this situation OP.
You are not unreasonable to be thinking logically about what your priorities are going to be once your baby is here, and there is a big possibility that attending a wedding fairly soon after the birth is not something you are going to want to do anyway, your body will be in the process of healing, you will be tired and a lot of new mums are reluctant to leave their newborn.
With that said, I am an ex-wedding coordinator and I can sympathise (only a little bit) with friend 1. Don’t get me wrong, she is not going the right way about it by shutting you out and being immature, but before you try and tell her exactly what your thoughts on her behaviour are, try and see it from her point of view.
Two of her closest friends (one of which is her maid of honour) have told her they may not be in attendance at the wedding she has been planning for 2 years. Despite how selfish it sounds, even the most reasonable person would have a hard time to not feel disappointed or upset. On the other hand a reasonable person would also understand that life doesn’t revolve around their wedding.
As you say, she seems to be striving for perfection and in my experience, these brides were always the most stressed the whole way through planning, and unfortunately in that state it is hard for them to see anything else but themselves.
I can’t say what she thinks and feels, but if I was personally in her shoes I would be most miffed about the limbo you and friend 2 seem to have her in at the moment (I think this especially goes for friend 2). As I have said, it is not unreasonable for you to think realistically about the situation, but what is unfair is not giving her a definite answer, and by the sounds of it you are sort of asking her to wait and see what the situation is, which is so close to her wedding date. Saying you might not be able to go doesn’t help an already stressed bride. Weddings cost money and a lot of the time are charged per person, venues and caterers often need final confirmation of numbers 2 weeks (sometimes even a month) before the wedding date and after that the couple will be charged for those numbers, if guests drop out after that the couple lose the money. Also there is the last minute rearranging of table plans, placecards, etc that is not pleasant for any bride near her wedding day.
I would let her cool off for a while, hopefully she will get her head straight and start understanding it from your point of view as well.
During that time I think it would be wise for you, and especially friend 2 to have a good think about your response to her wedding invite so you can then go to her with a clear cut answer. It is her choice whether she wants babies there or not (not uncommon anymore, there are quite a few couples that do not wish to have crying newborns at their wedding) and it is not unreasonable of her to put this rule in place but unfortunately she has limited how much you can be apart of her day, if at all.
I would say if you can’t be without baby for a few hours either to attend the ceremony or maybe visit as an evening guest (don’t know if using a breast pump could be an option? So someone else can feed your baby while you are out for an hour or so) then just say sooner rather than later that as much as you want to be there, you will have to decline her invite completely.
Friend 2 especially needs to think about this as she is maid of honour (more cost involved with things like dresses, fittings, etc). As much as your life doesn’t revolve around her wedding, neither does her life revolve around your babies. Friend 2 needs to weigh up whether she will take the risk of saying that she will attend the wedding (which can be hindered if she does end up going into early labour and that can’t be helped) or whether she wants to play it safe and potentially not go at all. Friend 1 deserves to have the chance to chose a new maid of honour who she can rely on to support her on the day.
I recently attended my cousins wedding where my other cousins wife was due to give birth around 2 weeks after. They declined the invite as they felt it was too risky in case the baby came early. The baby didn’t come until 8 days after the wedding but taking the risk wasn’t worth it to them.
I myself am 10 weeks pregnant and am due 2 weeks after one of my oldest friends wedding. Until I know how I will have my baby (may need to have an elective c section) I will have to think about whether I feel I can attend her wedding.
It does sound like you are trying your best to be involved, but let her cool down, have a think about what you are going to do, then try and talk to her again. If she keeps acting the way she is, then let her make her bed and lay in it. At least you have done what you can and are not keeping her in an uncertain state.
On the other hand, I don’t really understand why friend 3 is jumping on the band wagon, there is no need for her to. I would think once she’s there they will have a good time.
Again, sorry for the long post! I do hope whatever you do, the situation sorts itself out and ends up ok for all of you.