This reply may be a repeat, Sue, since I could not tell whether my first reply was posted. I believe you have the correct information about Edwin Motley and his second wife, Elizabeth Kidd, and their children. (I have the same names for the children that you have).Chaney Henshaw married one of these children - Mary Helen (Polly) Motley.
Edwin Motley was born about 1743 in Essex Co., VA and died in 1809 in K&Q Co. His parents were Henry Motly (1704-abt 1770) and Catherine Fogg. I do not have information on Elizabeth Kidd's parents.
If you can try again to write me at email@example.com I can give more information about my book, which has information on more than 13,000 descendants of Edward Broaddus of VA.