And, if they don't get enough nutrition the last month you can easily lose the doe before she ever gets to kidding time. It is a balancing act that gets dicier if a little doe is carrying a whole lot of baby weight.
Again - I will express my fears. In horses - baby size IS determined by mother My experience with goats has been otherwise... I've had baby pygmies be too big for their mothers when they were bred to another pygmy. I do a Nubian/Pygmy cross but it's always small buck to bigger doe - NOT the other way around.
It's not just the delivery you have to worry about either. Have you ever seen a doe with a prolapsed vagina or rectum? If that doe doesn't have enough room in the uterus for those baby(ies) - things can start falling out. It's not a pretty sight nor is it fun to deal with.
And, while being there to help is always good advice -if that baby is simply too large to fit through the birth canal - it's not going to matter how much you try to help unless you want to pay for a C-section and can find a vet to do one.
I'm not saying it can't be done - because the evidence has been posted by others. What it would boil down to in my eyes is do you want to take that chance? If they were mine, I would Lutalyse them and find a pygmy buck or other like-sized buck to breed them to.
Whatever your choice - I'll be sending prayers and good luck wishes!