My dd dropped her nap before age two also. Luckily, she never fell apart if she missed a nap (or I would have insisted she have one). It started at about 18 months and she'd miss a nap about every 4th day, then every other day. By age 2, she just didt nap. Bedtime was 7 or 7:15, and she'd sleep until 6:00-6:30 (still her wake time at age 7).
I think you can follow her lead if you don't think she's tired. My dd is really easy-going, so I knew that if she got fussy, she was tired and we put her to bed early.
