Wild Garter Baby Question

[Ariana]

Help! I found what I think is a newborn rusty/red garter snake in my driveway. "She" is only about 4 inches long and I thought she was an earthworm when my dog found her. I live in the Sierra foothills and it gets COLD at night (right now about 35 degrees but it is unseasonably warm for this time of year). I am worried the super warm winter we are having made her hatch too soon, and I don't know how she can survive a cold snap here. I took her inside for the night but I am not sure what to do with her. Any thoughts? I have never had a snake before so any advice is appreciated. If it is normal for snakes to be born outside this time of year I will return her to the outdoors tomorrow but if she is at risk I want to keep her indoors till the frosts are over. I have her in a container with dirt and rocks and a tiny dish of water. She is already hiding! What should I feed her? Her mouth couldn't even fit a fly!