Taz, I am a southpaw. Up until my last 2 rifles, I always shot right handed actions, no problems. I have 2 left handed bolts now but to start out and a single shot I can't see why she wouldn't be ok with a righty bolt. The only problem I ran into with right handed guns was the cheek plate, but not to many 22's have those. I would say go with a bolt, since she will unshoulder to eject and reload. A Lever might throw the case on her hand, semi auto's and pumps seem to blow them well clear of my face, but you said you want a single shot.

Oh and good for you not trying to convert her to right, I know I was told I did it all wrong and shoot right. Finally dad realized I shot much better with the left eye and said go for it. However it sure is a pain in the right mans world!!! BTW the only thing I do left is shoot a gun and bow, everything else is right...go figure!!!