I have found a birth of Walter E Howarth to William and wife Sarah A Ellison (b England) 19 Apr 1900 and also Florence 30 Sep 1904 (this time mother Sarah Elson). I have a suspicion that Sarah is actually Sarah Ann Elliston, b 1862 Ecclesfield as Sarah Ann Machen. She married John Elliston in 1881 but emigrated to USA in Aug 1890 with two children. I have found her son John in Pittsburgh (he died 1965) but, using "familysearch" cannot be sure if I have tracked down Sarah.
Does anyone recognise a connection with William Howarth and family?