A.B.
When I transitioned my daughter (now 17 months) I moved her nap later. If you are already keeping her up until 11:30, try 12. Then feed her lunch (then she won't be cranky). But the time you feed her, change her, etc. it may be almost 1:00. Then put her down for a nap. She will probably be tired enough to sleep 2-3 hours and then she definitely won't be cranky from 4-7 when she is awake again. That's what I did with my daughter and to this day she takes a 2-3 hour nap every day from 1:30-4:30. I get all the time I need and she is never tired.