This is a very serious step with lasting consequences. A lot depends on your relatives and how uptight they are about the rules and how much you would miss their company if they should shun you. If they are zealous JWs they may shun you if they find out you are Wicca, even if you do not disassociate. Being shunned is painful, that's why it is used by this religion. If you won't return they want you to be as unhappy as possible to deter others from following your example. They dent care a bit about you if you are not under their control.
I did not disassociate, but my JW relatives shun me because I remarried without a "scriptural divorce". Fifteen years later I am still married to the love of my life, but still shunned because I am such hussy, and my ex husband still refers to me as "your mother, the whore". Meanwhile, pedophile elders are OK if its been a few years since they offended and no one found out. It's a cult, they make up the rules as they go along.
In the long run it's your life and your family, so do what works for you, but make sure you have a support system in place in case your family does choose to shun.
I wish you well and hope everything works out for you.
Lisa Rose