G19 or a G26 are great carry guns, of course the 26 is smaller but 19 can be very accommodating depending on the person and the carry method/holster.
A G26 would be fine for a woman, has she ever used a firearm before?
Currently Glock is only producing a single stack model in .45 (the G36: slim-line, sub-compact) but it's assumed they'll try expand that line.