My dad knows I make comics but doesn't read them, which is probably for the best since I'm not sure he'd enjoy them. My brother has read a little bit but doesn't keep up -- I think he's more invested in my work because I'm the one who made it and because I'm really passionate about it, moreso than being interested in that sort of story himself. My mom used to read my autobio comic and was probably its biggest fan; I'm not sure if she would've liked my fantasy comic or not. It wasn't really Her Sort Of Thing but... heck, who knows! After listening to me talk about it a bunch, she said that she would really like to get the books and try it out and see if she liked it; unfortunately she never did get the chance. ;v; But she absolutely was supportive of everything I was doing.
I always was kinda secretive about my stories when I was small, so I think my family is sort of used to not really looking at my stuff unless I'm comfortable showing it to them. So for me to be quietly making comics and just kind of chatting about things I'm doing businesswise or how my readers are reacting to the story, without them necessarily reading it, wasn't weird for us. And like, back when I was living at home and doing two webcomics at the same time, it took up THE MAJORITY of my free time, and I was pretty protective of my comicking time (i.e., "I can't do that tonight because it's an update night, I'd be happy to hang out tomorrow though!") so it would've been pretty much impossible to keep it a secret, haha!
I did take my mom's advice on some things because I trusted her input. But my webcomics started after I got back from college, so, not really; I was old enough that whatever story I wanted to tell was sort of my decision to make.... I wasn't really drawing anything that I think they'd disagree with strongly, though.