Thomas Blossom's widow, wife of Henry Rowley

If Thomas Blossom's widow was Ann Helsdon(?), how come William Palmer wrote in his will that Moses Rowley was as dear to him as his grandson? That was of course Ann's second husband's (Henry Rowley) son and her step son. It has been assumed that Ann, the widow of Thomas Blossom, was the daughter of William Palmer.

Can someone unravel that?