As already stated, my husband and I are pretty affectionate with one another.
When my husband first started carrying he was very... stiff (for lack of a better word). He would not let me hug him, he never wanted me to touch him when he was carrying, he was paranoid, not letting me even put my arm around him...
Needless to say it made for a little tension in the marriage.
BUT... over time, the more he got used to things, the more he relaxed and the better things got.
As posted before, often I hug him and reach under his shirt and actually hang on to the grip of his gun, sometimes I'll fidget with the hammer even. He puts his arms around me and he rests his hand on my gun.
Sometimes, if I'm exhausted after a long day he'll carry me to bed and take my gun off of me and tuck me in.
I trust him and his guns as much as I trust him. He can put his arm around me and touch my gun all he wants to, that doesn't bother me.
Before I had my permit to carry John would carry a second gun for me to draw off of him if need be. Also, if anything happened where John couldn't draw it was my responsibility to get behind him, draw his gun in a way that made it look like I was just clinging to him for security and then use him as cover as I open fire.
If I were hugging him and something went down, he wouldn't hesitate to pull my gun if it were closest and I wouldn't hesitate to pull his.
I've said this before, but I'll say it again: my husband and I are more than just a marital team, we are a tactical team. If I can't trust him with his arms around me, with his hand on my gun, then I need to reconsider a few things. Likewise, if he can't trust me and my knowledge and ability than we need to do some work.
One, I think some relaxation would be a good thing. As long as you trust her, there's no reason why you should be worried about her hand brushing your gun. As it's holstered and secured nothing she can do to it (short of pulling it OUT of the holster and pulling the trigger) would hurt you.
Two, she does need to learn that nothing short of the above mentioned actions is going to make the gun go off if she hugs you and she touches it. She may be uncomfortable but she doesn't need to be.
What I would recommend doing is finding a diagram of your gun on the internet or somewhere else. Show her the parts and how it works and let her see what is required to happen for a gun to fire. You can tell someone over and over again that nothing short of trigger manipulation will make a gun fire, but unless they see why that's necessary, they won't get it.
I remember the first time I saw the internal workings of the 1911. I was SO impressed and my respect and comfort went up about 200% after that because now I KNEW how my gun worked and it made a world of difference.
If you know what you're doing, take the gun down and explain to her the working parts and how it operates. Let her handle the pieces and try to put it back together. Let her see how intricate it all is and how it is designed to be safe and secure.
Good luck!