Going up a size in diapers for length?

I have a super long torso, and it seems my baby might have inherited it. She's only 10 lbs and SHOULD still solidly be in the size 1 diapers (they go up to 14 pounds!) but lately I'm finding that they seem too short if that makes sense? She ends up with them wiggled down around her hips. We are fastening them tight enough, so thats not the problem. They are pampers if it makes a difference. Did any of you go up to a size 2 for the length? Were they too big in other ways (leg holes)? Do other diapers run longer? Help!