My parents were dead-set against snakes and were freaked out when I told them I wanted a python :shock:. I slowly and gently kept the subject open by providing positive facts to owning and keeping a python. I also showed them how much it meant to me by saving money for it.
Unfortunately they still didnt like the idea but when I rang mum from the reptile breeders saying I had put a lovely little Murray Darling Carpet Python hatchie on layby, she wasnt happy!
I thought if I rang before coming home, that gave them a little more time to talk or vent.
Snakey was on layby for a few months and I visited him twice a week to feed him and just hold him. I think that the layby period, besides allowing me to get all the cash together, gave them time to 'get use' to the idea before I brought him home. My parents were still upset when I brought Snakey and the heatmat home and set him up in my room but they took it much better than I thought.
This worked for me, but I wouldnt recommend it for all situations. Some parents might take it very badly. :?
Now I've got Snakey in a full sized enclosure in my room. I lock it (for their 'peace of mind'...LOL). I tend to his feeding and cleaning and they have nothing to do with him but are getting use to him being around.
My parents have come a long way and the other day mum even bought a large freezer container to put rats in the freezer as Snakey is growing fast.
If your sister can show that she's mature enough to care for a small python and is dedicated enough to tend to its needs (including financial), that can only help show much she wants one. I hope this helps, good luck.
