Ann - My records show that Richard Duty died in 1794 or 1795.The date on the will may have been the probated date, or it was signed just before his death.He could not have been Lucinda's father.Elizabeth Thomas was his wife, but I believe you are looking at the wrong family.
Lucinda's family did not come through this Richard who's brothers were Matthew and William.I don't know if her father was a child of one of the brothers or from a completely different family.
I checked the Mormon Family Search records and found an Ancestoral record for Lucinda.It shows:
Father - Richard Dutyb: 1754 (N. Carolina); d: 1822 (Knox Co., Indiana) Mother - Sarah Pinsonb: 1788 (N. Carolina) They were married in 1788 and had 14 children.
You can find this by going to "familysearch.org".Type in Lucinda Duty with Richard Duty as the father.