You can also find used Glocks at decent price (or at least you used to be able do that

It is rather like a Honda Accord. It is very reliable, inexpensive(relative terms), dependable, long lived and It has many after market parts.
That said, like a Honda Accord it may not be exactly what the person wants and may not be the best choice for that person. A firearm especially a CCW is a very personal thing thing and the choice of a CCW is very dependent upon many personal preferences. A person's preference is not necessarily good nor bad, it is just that, a preference.
Buying a CCW is rather like buying shoes or a tie for someone. There is a lot of personal choices involved.
A Glock 19 can easily be rented at a range. Have her shoot it several times first. That is the first part of the choice. Does it fit the hand and can the person hit the target with it.
On the other hand if you simply buy a Glock 19 and it does not work well for personal reasons reselling and getting most of your money back should be easy.
IMO with any new CCW holder, decide how the CCW will be carried and let that govern the type & size of the CCW. Then and only then decide what what caliber is most accurate for that person in that CCW type. For instance a .32ACP is not my first choice but if that is the caliber that allows that person to hit a target consistently (due to recoil/noise/whatever) then work around that limitation.
YMMV