M.K.
Hi D.,
I, too, transitioned my kids to "big beds" at 3yrs old also when they were ready to follow rules and weren't as impulsive as a toddler. My daughter kept her nap for another half-year. But my son dropped his nap completely. As long as your daughter is getting the recommended amount of sleep during a 24 hour period, it doesn't really matter if she naps. But I strongly recommend giving her some independent "down time" via quiet time in her room. It seems to make a huge difference to my kids' behavior.
Nightime/wake time, I found a wonderful nightlight for my kids that glows as a blue moon at night and then changes to a yellow sunshine when it is time for the kids to get up. It's set on a timer...so *you* get to set the time for when it turns to sunshine! If the moon is on when they wake up, they must stay in the own rooms (ideally their beds). If they come into our room too early (and I know what time the sunshine turns on!), we send them back to their rooms. Once sunshine is up, they are allowed to come out of their rooms and come into ours. It's a nice way to start our day -- both kids running into our room. Of course, if a child needs to use the potty at any time, s/he can go. The kids get trained pretty quick with this nightlight, so I found this pretty easy. You can find this nightlight online at www.goodnitelite.com
As for quiet time, my kids stay in their own rooms, playing quietly. Teaching my daughter was easy. But teaching my son was pretty difficult -- it took weeks before he would voluntarily stay in his room. My rules are they must stay in their room (unless they need to use the bathroom) and they can play with any quiet toys (doll house, blocks, coloring, etc.) Quiet time is one hour. When quiet time is over, I open their doors and the fun resumes!
Hope this helps.