22lr. Would be what I got her.
. If she is new to shooting then see needs to start out with a rifle that she can spend more time with and keep doing the basics of Basic Rifle Marksmanship (BRM) over and over again. The 22lr is not a week cartridge it can and has kill more deer and HUMANS that just about any other cartridge out there because people think it is week and a toy.
I can shoot anything in a rifle recoil doesn't bother me. But I have more fun shooting rimfires that anything else.
Once you and her get past the "I have to shoot something big" phase you will learn this too. Shooter fatigue is hard to teach against because both of you may not know what it looks like.
Teaching BRM is more important than what caliber she uses.
Even the 223 (Of which I have 2) can have too much recoil for some shooters. Your best bet would be to get her a nice Savage or even better CZ Rimfire and teach and practice with her till she is ready to move up. If you don't want to keep the rimfire (Not sure why you wouldn't) you could trade it in on a bigger rife in a bigger caliber.