I used to think it was taboo too, but we have photos in our bathroom. A team shot of my husband's uni rugby team hangs behind the toilet. A photo of a frog that took up residence in his toilet when he lived in Australia is also in the bathroom.
I can picture photos of kids in the bath, mom with her shower cap on, dad shaving, in the bathroom, why not. I am sure that there are rules about these things, but I think rules are made to be broken. So long as you have some space in which your eye can get some respite, no harm in photos in every room.
now to answer your question- we've got a collection of 7 wedding photos (4 5x7, 2 8x10 and 1 11x14), a collage of infant photos (4 3x5), and a set of 6 4x6 photos in the bedroom, which I swap out every so often.
in the livingroom, we have a family x-mas shot , two collage frames, and hubs uni and grad school grad photos.
in baby's bedroom, we have a set of 8 4x6 photos of my and my husband's dogs.
good luck to you and yours,
F. B.