Simon and Catherine had 4 children that lived; Ann married Peter Geauvreau; Thomas married Monica Evans; Sarah married Joseph Munger and Prideaux married Catherine McKenzie.
Some of the surnames that the children of those listed above married into include; Hayes, McKenzie, Sanford, Fox, Scratch, Skinner, Bruner, Bowring, Kalchthaler, McCormick, Ferriss, Larabee, Wigle, Fox, Harris, Elliott and Allen.
If you can get your hands on a copy of "Simon, Peter and Polly" by Madeline Hillborn Malott, she has entered in the back of the book, small amounts of family information on the various Girty/Mallot family lines. I was told she was printing a second book with additional information on descendants listed in it, but I'm not sure if she has or not. If you are a Girty or Mallott descendant I recommend the book. It is informative and makes for an extremely intersting read.