How many hours after waking does your LO take his/her first nap?

For the looooongest time, LO would be tired as little as one hour, up to two hours before being dead tired and ready for nap#1. Now, at 8.5 months, she's going onto 3 hours before even showing the slightest sign of being tired. Sometimes I feel like I should force her to nap because she's just too busy playing to show me that she's tired.

Insight?