As I thought may be a possibility, 13 ABY seems to be too early a start, now that I’ve done more digging into the founding of the New Jedi Order’s praxeum and how much time it took to grow to a point where every person hasn’t already been written about.
The praxeum on Yavin 4, founded by Master Skywalker in 11 ABY, only had a handful of students its first year. The next year noted in my sources is 14 ABY, with a longer but still very particular list. There is a limited period of about 15 years before the Yuuzhan Vong invaded the galaxy(!) and trashed the praxeum, which was relocated afterward. I don’t want to get into (or even close to) that complex time period or later, so sometime before 20 ABY.
The thought’s come to me that maybe earlier is the answer. There were many Jedi before the “Order 66” purge and it would be easy to insert a character or three there. Even afterward may work, but we’d have to be very sneaky to avoid Vader. There are also certain unique ideas I’ve thought to try that would be easier to work with if my starting point is before the purge, when things like lightsaber crystals were outlawed and buried or destroyed by Palpatine.
Within that time period, I think I’d want her to be a new Padawan at the point of Order 66. Too young to have been drafted into the Clone Wars like Ashoka, but beyond the youngling stage where she’d have been stuck at the Jedi Temple and killed by Vader.