If I had a plumber in the family, I certainly would not expect him to hurry over and fix my overflowing toilet. What the heck? If I were the plumber in the family, I certainly wouldn't want everyone else calling me for all their little plumbing problems.
That doesn't mean if I noticed my mother-in-law's toilet was running incessantly that I wouldn't offer to fix it for her. But they should not have an expectation that I'm going to be doing free plumbing for everyone in the family.
And if my brother discovers that all the galvanized pipe in his house needs to be replaced, I might give him my expert advise on how to get it done properly and at the least expense...by another plumber. But I'm certainly not going to do it for free.
I have one sister-in-law who is both greedy and needy...and makes more money than I do. I'm a pretty competant DIY, and if I'd let her, she'd have me working in her house every weekend. Sorry, no. Some peole are "users," and she is one.
As a photographer, I am torn with family for only one reason: I do deeply believe in the heritage importance of the portraits that I do. So I will do a set of family portraits free simply for the sake of our later generations. But that certainly doesn't mean I'm going to do all the kids' birthday parties, senior pictures, weddings, et cetera, ad infinititum, ad nauseum, for free.