jade - I've struggled with this myself. I actually have more family pictures up on the wall than when W left but that was because she took a lot of our art and I pulled old pictures out of the closet to cover up the blank spaces.
I don't know what the "right" answer is - but it would be whatever feels "right" for you. It sounds like your kids get some strength from seeing them too so that's a factor for you to consider. I know that originally I felt like stripping all traces of W from the house. I haven't though but neither have I made the house into a shrine dedicated to W and our former MR. I expect over time that I'll get some new art that I love to replace most of the family pictures that are up but there are a couple like the collage from D24's wedding that will probably be a permanent fixture in the house still.
I don't know if that helps or not but it's the best advice I have.
On BD H52, W50 T27, M26 S21, D23 BD-9-Mar-16 D-15-Jan-18 Final-19-Apr-18 I am a storyteller. The story may do you no good. But a story is never for the listener. It is always for the one who tells