From what iv found in my experience,
1. You willingly lent it for lawful purposes
2. The loan does not exceed 3 days.
3. She has a current Handgun Safety Certificate (OR)
4. She remains at all times within YOUR presence
However, if you are carrying ammo for the handgun and you somehow get charged with CCing the weapon (shirt came untucked etc) with PC 12025(a)(6) allows it to be charged as a FELONY since it was registered to YOU and NOT HER!
So be careful of that.
hope that helps.