I've been looking at a lot of author websites and bios in the line of work lately, and have been amazed at what I've been learning. To wit: Authors' ages, education history, work history, family make-up, family members' names--spouse, kids, parents, in-laws(!)--pets' breeds & names.
No one needs to know that stuff except family historians and stalkers. The former can get it from you personally. Don't help the latter.
Unless you've written a book on childcare, adoption or parenting, we don't need to know about your kids. Nor should we see their pictures on your website if they're school age or younger. If they're teenage or older, get their permission first.
Similarly, if you haven't written a book about animals, we don't need to know much--if anything--about the pets in your life.
Unless your significant other is your cowriter/illustrator or famous, we don't need to know his/her name either.
The only reason to indicate your age is if you're a Wunderkind like Christopher Paolini or a venerable ancient like Studs Terkel.
It's OK to mention your family (briefly and preferably not by name unless you've written a memoir) on the bio page of your website. Other than that, focus on yourself and your work. Rule of thumb: If you wouldn't put it on a job application, don't put it in your bio.
Joe Shmoe lives in Sullivan County, N.Y., where he spends his non-writing time chest-deep in cold water, hoping to catch a record trout.
Jane Shmoe lives in Alexandria, Va., with her Chinese engineer husband Phil, 5-year-old twins Amethyst and Tourmaline, and Kerry Blue terrier Seamus.
By happenstance, a few days ago Agent Kristin blogged about TMI (Too Much Information) in authors' query letters. Read and wonder!