357 magnum revolver should be a consideration. Load it up with 38 specials for most practice and the 357s for some practice and carry.
Get her a .357 SIG and you have the .357 Magnum 125 grain ballistics pretty much, but the capability of having more rounds in a smaller frame platform.
"Do I reload to shoot more, or do I shoot to reload more?" 30-378 Weatherby, .300 RUM, 7mm Rem Mag, 6.5 Creedmoor, .223/5.56, .375 H&H, .40 S&W, 10mm, .357 SIG