One of the more famous accounts of this is when Andur Sunrider a jedi knight killed by gangsters only to have his wife Nomi Sunrider take his light saber and defend her and her child. Nomi Sunrider would latter become one of the most famous jedi masters of the time.
Ah, beat me to it.
Also, let's not forget the Green Jedi/Corellian Jedi. They're known for their familial ties, and the Council may not officially like it, but there's not really anything they can do about it. At least not without casting out a large part of the Order and cheesing off Corellia in the process.