I feel like you shouldn't be thankful for anything that your family does for you. Because they forced you into it in the first place. They didn't ask you to be their son/daughter -- they forced it upon you. So of course they support you and stuff, it's normal since you're family and they're nice people. What else are they gonna do, right? So stuff like that doesn't deserve special thanks since they don't have much choice and neither did you.
Now if a stranger did something nice for me, I'd be thankful for that.