She may be the one who married Godfrey Brown at Newport on 12 April 1770. But since Phebe is a common name, it may have been another individual of the same name. The marriage record says Phebe was of Portsmouth. (see notes for her father)
Godfrey & Phebe Brown witnessed a Richmond, RI, land deed on 29 May 1773, between Gideon & Anne Worden of Portsmouth, RI, and David Allen of RI. Allen is a common family name in southern RI.