Hey Sarah - Like Creations, we moved fairly quickly to one nap at 11 months.
Couple of options for you...
1. Shorten her AM nap more... wake her after 30 mins. Then PM nap about 2.5-3 hrs later and let her sleep as long as she likes.
2. Push her to 1130am and then just let her nap as long as she likes... if needed, do a CN or EBT depending on what time she wakes up.
Either is a good option, but I would recommend the second option as the first can leave you with a very crabby kid until that PM nap.
I also had a 10 hr a night girl who never tacked on lost sleep... until the move to one nap