Oh yes. The genealogy end of things has consumed me for some time.  There is an updated tree you can access here.
Please note:  These novels have been written over twenty-five years, and the first one was published before the internet made working without a library possible and even more relevant, before I had software to help me keep track of chronologies.  So you will find shifts in families. More or fewer children than you thought, different names. I welcome any questions about the tree that will help me (or better said, Polly Edwards, who did all the heavy-lifting/programming) fine-tune things.