I am certainly no expert on fit or fixies in general but I think a bike like this 42cm frame from Wabi with 650c wheels would fit her perfect. 697mm is a 27.5in standover and the TT comes in right in her sweetspot.

I know this is way out of her price range. Anybody make more reasonably priced fixies with 650c wheels?

Edit: I found a Fuji Track classic 43cm with 650c wheels that looks like it has a comparable standover and TT length for a little less but still too much. If I were you I would look for one of either of these bikes on the used market. Maybe there are others out there lower priced. Good Luck!

Edit: Here's a 43cm Fuji Track for $350.00 neg. I know it's in Philly but they're out there anyway.

http://philadelphia.craigslist.org/bik/3610330911.html