Honestly Joan, I think you have already found out what happened to this family. The children appear to have died young and the father took his own life... in all likelihood Margaret/Mary was probably also deceased before George did this.
I did not find a death record for her but neither did I find a marriage or any other listing for her after their second child. I see that there are several other Chandlers in Hatfield and all are of German descent so it seems plausible that they are all related, probably fairly closely, in some way or another. I will keep digging and let you know if I turn up anything different. Bob Birt