J.☯.
If she is going to sleep (at naptime and at bedtime) just fine, them I'm thinking the problem is not the paci. My guess is that her sleep needs are changing.
If she is waking up cranky or is showing signs of being overtired, that's one thing. But if she's in a pretty good mood most of the day, she's probably getting enough sleep. It's not unusual for her to need a little less sleep at night. If she is getting eight hours of sleep at night and she's getting a nap during the day, it's likely that that's all the sleep that she needs.
I think I would consider having for bedtime a little bit late. No way would I want to be waking at 3:30 in the morning! My kids both slept about 7 to 8 hours a night with a 3 hour nap at that age. Wow was I happy when they gave up their nap! They sleep for 11 to 12 hours at night, then!
Sleep needs change, and I really think that's what's going on here.