Women are individuals, just like men are.
Just because some other woman halfway across the country likes some specific firearm doesn't mean your wife will.
Just because 1,643 other women like the gun doesn't mean your wife will.
If a million other women jumped off a bridge, would your wife do it too? (Sorry ... just channelling my mom there for a moment! )
What I'm getting at is that
the only opinion that really matters here is the one belonging to your wife. You need her opinion far more than you need those of anyone else in this thread.
But as far as finding guns for her to try, here are a few within the category you suggested (small 9mm):
Glock 26
Glock 17
XD-9 subcompact
XD-9 compact
Kahr P9
Kahr CW9
S&W M&P subcompact (replaceable grip panels makes this one very attractive for those who may need to share guns between shooters with different size hands)
Those are all going to come in at different price points & I don't know the market in your area. Keep in mind, though, that unless your wife has expressed an interest in
carrying the gun, as long as the gun fits her hands she's probably going to be more comfortable shooting a heavier, larger gun than she will be a shooting a lighter or smaller one. Just the way the physics of recoil works.
Do go read my earlier link.
pax