Hi A., I remember our DD went through a phase around the same age, where she was even getting up around 4:30 a.m. Yikes! We would be so tired, we'd pull her into bed with us to see if our warmth and sound breathing would entice her back to sleep, but she'd squirm and wake us up, so we found that putting her in front of a kid-safe video in the living rm. worked for us. The phase only lasted a short while, but long enough that both my DH and I remember it!
I can also say that later to bed, doesn't = later up in the a.m., it can actually cause some kids to wake up earlier because their biorhythm becomes neurologically disorganized. Earlier to bed and more sleep actually cause a child to sleep in more. I think Dr. William Sears mentions this on his website.
If you suspect that the afternoon nap is interfering with nighttime sleep. you might try telling her that she should just lay down on her bed for 20 min. without moving a lot or talking (show her on her bedroom clock what number the minute hand needs to be on in order to get up). This method has helped my son tremendously, he often will fall asleep watching the clock!) You can even lay down with her the first few times to show her what it feels like. Tell her you are going to wake her up in less than an hour, if she falls asleep. That way you can both have a nice break, yet not revive her for the next 9 hrs!
A warm bath, stories and laying down with your kid, scratching or massaging their body, rocking chair, singing lullabies are all lovely ways of bonding, ending the day and helping kids to drift off to sleep. Like you said, sleep is good for the brain, kids this age need 11+ hours/day.
Wishing you all lots of ZZZZZ's,
Mama in CA