@Alet Jasper (Pletjes) - my 10th-great-aunt
Wikipedia says"Benjamin Rush's great-great-grandfather, John Rush, came to America with his wife, Susannah (Lucas) Rush from England in 1683. Susannah Lucas was first cousin to William Penn, who established Pennsylvania. Their mothers were sisters."
Anne and Elizabeth don't fit - unless one of them had another marriage. So was there a fourth daughter who married Mr Lucas?