I'm assuming you've never kept snakes before, and you've done your research.
The snakes you mentioned aren't very good snakes for beginners. I recommend you start with a ball python, corn snake, milk snake, or king snake.
Alright. Try to have a mature conversation with your mother. Tell her that these snakes are NOT dangerous, and that hundreds of thousands of people keep them as pets. Everyday driving is more dangerous than handling these snakes.
You need to convince her that snake aren't scary demonic reptiles. If you know someone/somewhere that will let you hold some snakes, go show her. Hopefully she will realize that snakes make terrific pets, and are very calm.
Also tell her how snakes make no noise whatsoever, no mess outside of the cage, and are in fact very clean animals.
I'm not sure what to say about the whole furry deal. I know that it's very easy to buy corns/kings/milks that eat frozen mice, and there will be no need for live mice for that. It's not like she has to witness the snake eating all the time. Good luck.