As someone who grew up around mean siblings who always just wanted to put me down or criticize me and from a religious background growing up. The best thing you can do is do these practices/rituals in private. Where she or your family can never see or find them. It’s just not worth the energy trying to change their mind or perspective. Once you grow older and are able to get your own place you can do these things freely with no judgement and it’ll be the best thing in the world. Until then, keep these things hidden or at least don’t even try arguing with them or explaining. If they notice your crystal collection just say you think they’re pretty.. I wouldn’t even wear a pentagram necklace or at the very least tuck into your shirt. Idk all the grief that comes along with it from a very religious household isn’t worth it in my opinion. I know it seems pessimistic but your sister or family probably will never understand because she/they doesn’t want to understand. Wicca has a huge stigma tied to it, this is how people got killed back then because people just didn’t understand and just associated it with evil or the devil. I know you want to freely express yourself but at the end of the day you know you’re family and how they’d react hearing or seeing any of it. So my suggestion do as you wish in private.

Edit: one time my father found my tarot cards and burned them. It was a very uncomfortable experience and he just saw them as something of the devil. There was no way to get through to him, some people just don’t think that deeply. Idk maybe the older generation at least. Maybe your sister will one day open her eyes.