I would suggest keeping the rule that only you can go into the gun safe unless it’s an emergency. It’s your guns and you should be asked to use them, they aren’t shared property like a couch or television. You acting like her dad is ironic because she is acting like your child. I suggest not budging on letting her touch any fire arms until she will voluntarily learn how to properly handle firearms. That means explaining what she should have done when loading a rifle in front of her friend, how to check the chamber, clearing, flagging, and just the generally mechanics of how guns work. Explain how important a loaded gun is vs. completely unloaded, chamber always checked. As for the friend, I would watch out with how she acts around you. Especially with the fact that your wife will probably talk about all the details from this event and outcome. If your wife resents you and talks down on you because of this and the friend shows that through her actions, then you know that the comment that you treat her like you’re her “dad” is just a manipulative comment because she can’t control you/ get her way. Seems like this could lead to some bigger issues down the line.