It took me a bit of convincing to get my mom around the idea that I'm going to keep a snake in the house. Mostly because she is(or was....she's coming around now that I've told her so much about bp's) deathly afraid of snakes ever since she was traumatized in high school when a bully shoved a garden snake down the back of her shirt. What I did was I researched and researched for the last 3+ months reading and absorbing all the info I can. Then I regularly talked to her about snakes. I also started watching anything and everything snake-wise on the Animal Planet channel and stuff. I was talking about snakes so much, it sorta broke down that wall she had around her, and one day while we were sitting outside on the deck, she just started asking me questions about them. And I answered them easily. I think she was testing me to see if I was actually serious about this. After she realised I'm not giving up and this isn't a fad I'm going through, she finally caved. I knew she caved when one day I came down stairs and she said "hey cody, grab me something out of the trunk of the van". I went out there and she had gotten me a 20 gal tank at a yard sale to start me off. Since then she's gotten over the idea of having a snake in the house. She even admitted she'll probably be over the fear all together and start handling my bp when I get her in a week or so. But it'll take a while still.
Basically you gotta take your time. You can't just force the idea onto her. Do all the research you can, and then show her you're serious about this. Tell her some stuff like ball pythons are virtually harmless, and if it ever did get loose, you should be more worried about what your dogs would do to the ball python, rather than what the bp would do to your dogs. And bp's rarely bite people. And when they do it's either because they're still babies and still think the worlds out to get them, or they aren't being handled enough to be used to human touch. Both can be solved easily by regular handling. And a bp bite barely hurts. Just tell your mom stuff like that to assure her that it's not going to be some huge monstrous snake from hell.

And I'm done....I rambled again....shame on me...