I too didn't want to be a bother, so for Scottie I had only asked for a few pictures and I got pictures of him when he was 3 months and then 5 months. I also asked for pictures of his parents. For his upcoming baby sister, I've asked for recent pictures and if they had any older pictures. So I got 1mo, 2 mo, and current, total less than 5 pictures. And of course pictures of parents again. I assume they're really busy so didn't want to seem annoying and ask for more even though I'd want to!
I figure I'll have plenty of time to take pictures once she arrives