I like to "get in" and "get out" when in line for characters...especially when the line is long.
We were in line for Chip and Dale (this past June)...and this family (of 8 or so) in front of us took WAY too many photos. Mom with Chip and Dale, Dad with Chip and Dale, each kid (2) with chip and Dale, Aunt with Chip and Dale, Uncle with, then one of all of them, then Aunt and Mom and so on and so forth. I was soooo annoyed (and I don't really get annoyed!). It was hot and I think they took MORE than enough photos...
But, if you have 2 kids...I really don't see the harm in one of each and one together...that is definitely not going overboard!
Good luck...and if you do annoy others, hey, you will never see them again!