You do have your younger sister to think about as well. I will share some of my experience with my step mom.
Through several emails and some discussion in person over about a month, she knew I no longer considered myself a JW. When the realization finally dawned, it was not a nice scene. She said some pretty horrible things (whoever said words can't hurt, were wrong). She even went to her elders (different town, but they knew me) and told them I was apostate, told my younger brother, said she cut me out of the will, never wanted anything to do with me ever again, I was dead to her. Now, this is coming from a woman that has a DF'd sister and neice that she never ever shunned, nor did she shun my younger brother either time he was DF'd, and maintains a relationship with her brother (never been a JW) who is a convicted sex offender.
I told her I was sorry she felt that way, she was closing the door on our relationship, not me, and that I'd always be here for her.
We did not speak for several months. I made no attempt to contact her, nor she me, until one evening she showed up at the door and asked to see me. She apologized, said she did love me and wanted a relationship with me regardless of my beliefs. We have an agreement we do not talk religion, and she has upheld that. No meeting invites, no Memorial invites, no literature.
BB