Hi Everyone,
Just an update in case others are experiencing similar problem. Instead of doing the 5-15minute increase in A time, I just kept my DD up for 3 hrs. This was a huge adjustment from the 1.5-2hr A time she was used to. The first few days her naps were 30min-1hr, and she was tired by 5:30p. A few days at the end of the night she was cranky and cried for 5 minutes or so before going to sleep. After about a week, she started doing 1h15min-1.5hr naps. Some days are better than others (she's teething so that complicates things), but all in all it is going well.
One trick I found useful is although she was showing tired signs (rubbing eyes, sucking thumb, pulling ear), if I changed the activity she would be able to stay up longer. I also found that once she started crawling more her naps were longer when she spent most of the A time exploring our house!
Thanks for all the advice.