Can people with significant age differences can be friends?

I am 32 and happily pregnant. I'm in a pregnancy group hosted by my town library. A few months ago I met a 20 woman pregnant with her second. At first she seemed mature for her age but as time has gone on, I am noticing how much on different levels we are.

She is very irresponsible both with her child and money, her and her even younger husband are always behind on their mortgage, always threatening for it to default. But she is never concerned, she just goes about life. She's unconcerned about anything involving her child too, never taking him to doctor appointments or keeping up with his hygiene or nutrition, and generally just letting him run wild. She's also super argumentative, and constantly jealous of other people. It all seems so juvenile and immature, and all I can think is it's her age.

Now I'm letting the brief friendship fizzle out because of it.

It made me wonder, do any of you have big age gaps in your friendships? Do you think it's possible?