Update:

Today I took Rita out of her cage and into my hands for the first time! I saw her basking and stuck my hand in just to let her smell me. She was very curious, and after a while of leaving my hand in there with her I just tried to sneak a finger under her. It worked! I lifted her out of her cage and while she was a little fast paced, she didn't bite or even musk at all! She just went through my hands. I only did this for a couple minutes as I did not want her to get too stressed out but so she could start understanding that I'm not going to eat her haha. This is such good news to me as the last garter I had was insanely wild. I'll try again tomorrow before feeding her, and hopefully she keeps being a little sweetheart! ^_^