I get this all of the time, both teaching basic CCW stuff, and working at a gun counter.
"My wife can't rack a slide."
This is normally said by a husband, pointing at his average size, average health, wife.
WRONG!!!
Every single time, a couple minutes of proper instruction has them racking the slide. Unless you have severe muscle problems, arthritus, or bone disease, you can rack a slide. The % of the population that actually can't rack the slide of a semi-auto is tiny.
Read Pax's link that has been put up repeatedly. Then have somebody (not you) teach her how to do it. (the biggest mistake I see is going slow, and not using the strong hand to "punch" the gun)
This is nothing personal, but husbands/boyfriends CAN'T TEACH their wives or girlfriends. I've taught hundreds of people, but I can't teach my own wife. It just doesn't work.
And like pax said, if she's happy with what she has, that is up to her. Your concerns are your own. The most important thing is that she is confident with her gun.