I don't think you're being childish. We live in a society that is on Facebook, and parents want the pictures and the updates and all the cute stuff, so wanting to be acknowledged for providing it is not childish. It takes a fraction of a second to like a picture. It's not hard. That being said, not everyone participates in Facebook farther than just scrolling and looking at pictures...lurkers.
So it may not be intentional. I would probably overlook it, but I would not go out of my way to cater to one parent in terms of pics and texts.
As for the baby being on the floor while your mom changed the diaper, that wouldn't bother me. If I liked your care for my child, that one little situation wouldn't be a big deal, but every parent has a different comfort level.