Fine Art photographers more or less give up the right to take snapshots of their kids.
Most fine arts don't truly have a vernacular form. One does not casually make sculptures about one's kids. One does not write a sonata about one's trip to Disney World. Photography does, and boy does it ever. Almost everyone makes photographs of random crap. Some artists even attempt to co-opt this stuff, making collages of found photographs and so on, trying to express some essence of Americana or whatever. The only other nominally Fine Art I can think of with a vernacular variant is fabric arts. I suppose that if you sell enormous macrame pieces for millions, you probably have to be careful about knitting socks for the cousins.
A Fine Art photographer, like any other Fine Artist, is working away at an oeuvre, a body of coherent work. That body of work has many things in it, but not too many. Enough to support the market, not enough to dilute the value. The artist's brand relies on this. Just as Rolex cannot design and build an inexpensive digital watch the Fine Artist cannot be seen as making a huge body of lower grade material. The body of work that backs up the brand must remain relatively pure if the brand is to remain valuable.
Sally Mann might have a shoebox or two full of color snapshots of her kids, but I'm gonna bet that she keeps pretty close track of them if she does.