They were generally polite; there were a few nasty messages early on, but that tended to happened before anyhow. There's little contact, but religion might not be the only reason for that. My school-age children haven’t even heard of JWs (so far as I know). My non-JW in-laws were relieved their sister/daughter's 'Christian Phase' was over.
(Edited to add that, in fact, I'm not sure that I've ever told my parents - although I've been out since 1998. They must have drawn an easy-to-make inference, or my wife told them. I know I've never had a conversation about why with my parents: I tried with my sister and that went badly, I did with my brother and he's out too).