Why, is she disappointed she isn't getting to play auntie? That's about all the "friendship" her friends are probably capable of now. Personally I'd rather ditch those friends and make some new ones than suffer a child's birthday party or vapid conversation about diapers.
What surprises me is that the women in the article have moved on themselves. They've left their hometowns, and in one case the country, and they expect their friendships with their childhood friends to remain unchanged. I have no close friends from that period of my life. I do have a few from university, but it is the exception, rather than the norm, for friendships to withstand major changes in life - such as moving abroad or having children. Unless you and all your chums stay in the same town you grew up in, your experiences and theirs are going to make you gradually grow apart, most of the time.
They should make new friends instead of expecting their social circle to be complete by the age of 20.