Unlike his brother John, Philip did not become a freeman, and a Bridgewater town meeting record of 8 May 1685 (MD 16:249) shows that he was incapable at that time of taking care of himself, and his nephew Joseph Washburn agreed to take care of him. Philip's brother John had directed in his will that "my Son John take Care of my Brother Phillip," and this is probably part of the reason why many people (e.g., Davis, Savage, Mitchell) have stated that Philip had no children of his own.
The fact is, though, that Philip married late in life Elizabeth Irish, daughter of John and Elizabeth Irish, and they had a son John, who married Lydia Billington, and daughters Margery, who married Josiah Leonard; Mary, who married Daniel Pratt, and Elizabeth, who married Joseph Amory (MD 15:247). Bowman (MD 16:249) refers to a 1702 lawsuit regarding Philip's children's suit against their uncle John Irish. Proof that Philip had a son John is found in Ply. Co. LR 10:1:466, in which John Washburn on 8 December 1708 sold land to Samuel Bradford, "which my honored grandfather John Irish deceased" formerly possessed. Philip was still living on 19 August 1700, when he was mentioned in a Bridgewater town record (MD 16:253).975