Okay. I understand how you feel. I wasn't able to have snakes as a boy either because my mother was/is "extremely afraid" of snakes so I didn't really pursue it. However, as an adult my wife and I purchased our teenage daughter a corn snake and haven't regretted it. We have enjoyed the first one so much we now have two.
I also understand your mother's point of view. Initially I too had a problem with the idea of feeding a dead mouse to a snake. I wasn't keen on dealing with the dead mice or, more importantly, keeping them in our freezer! This is what we did: First, my daughter and I did independent research on pet snakes and we both came up with corns as good pets. The only problem was the mice. I too didn't want to deal with the mice but wasn't entirely closed minded to the idea as long as we didn't have to deal with any larger prey- no big fat rats. Next, I found out that one of my business associates kids keeps an adult corn snake so I arranged a visit with them to see how large the snake was, check it's temperament and watch it eat an adult mouse. This way both me and my daughter could assess exactly what we were getting ourselves into- the worst case scenario I guess you might say. Much to my surprise their snake (about 3.5 feet long) was very relaxed and also very beautiful. It's skin was soft, not slimy or scaly and seeing the look on my daughters face when she first held it was enough to melt my heart. On the other hand, I hadn't seen it feed yet so... next, their son thawed out a mouse in a cup of water and placed their snake with the mouse. At first I felt a little sorry for the mouse and was a little grossed out seeing it in a cup of water but once again I was surprised. I had expected a violent constriction, blood, gore and general snake on mouse mayhem. Instead, the snake simply picked up the mouse and began to swallow it whole. Within a few minutes it was in it's belly and their son placed the snake back in it's cage. Not only did it not bother me as I had expected, but I was fascinated by the simplicity and calmness of their critter. After discussing the whole thing with my wife, who is really quite agnostic about it, we decided to get an Anery corn and later an Okeetee.
Perhaps you should do something similar with your mother. She's going to have to live with a snake too so she may as well find out what it's all about. As with us, your mother may find out it's not really as bad as it first seems and corn snakes make excellent pets. Good luck!