First off, Congrats on raising a sleep-healthy child! It's so important for her development.
Secondly, I would talk to her pediatrician before you change her routine. It sounds like she's doing great right now.
Try moving her nap up by 30 minutes and see what happens. Also, maybe try to get her outside or to play a little harder/have more active play after she wakes up. Maybe this would help get her tired.
If she's not fussing at bedtime and sits in her bed for a little while after you put her down, that's OK. She knows how to play by herself and keep herself entertained and that's a good thing! :)
I would not suggest waking her up in middle of her nap. Children need to complete their sleep cycles without being woken up. Being woken up can have negative effects on their sleep schedules. There's no need to cut back on her naps at 2 1/2 years, she won't be going to school for quite awhile so I don't think you need to worry about that. Her habits will change so much by the time she starts preschool or kindergarten anyway.
There's a great book my sister loaned me by Marc Weissbluth- Healthy Sleep Habits, Happy Child. I recommend this book to many people. He's always been right on target with the stages my daughter has been through.
All that being said, every child is different. Some children stop needing naps completely at 3 years and others don't get rid of their naps until they're 5 or older. My sister used to come home from kindergarten and go right upstairs to lay herself down!
Good luck!