She definitely needs to be the one that decides and may very well surprise you. My granddaughter has been shooting with me since she was 8 and is now 18. Last summer we went to the range with all my pistols from .32 to 45 Kimber custom carry. Her choice after shooting all of them was A Canik 100 which is basically a CZ PCR but with a safety instead of decocker or a CZ compact but with alloy frame. She like the Kimber a LOT but thought it was a bit big for her although she shot it well.
As others have suggested let her shoot a bunch and then chose. So many variables from fit to recoil to comfort to safety vs decocker etc etc.