Hi - have I got this right as you say you are tracing the Ushers but that's not how your message reads
Your paternal grandfather was Thomas Lilley
He married Phillis Widdowfield
Phillis was the daughter of James Widdowfield and Mary Usher
My grandfather had an elder brother William ( born 1866) and three sisters. Two of the sisters never married but I have been unable to trace anything for Ellen.
Your grandfathers surname was Lilley so are you looking for his sister Ellen Lilley b 1872 Middlesborough?
If so - she was still with her father in 1901 at 11 Cross St (1881 census) plus sister Emily - no Martha
Is this Martha's marriage? If so - if 2 sisters remained unmarried - perhaps it was Ellen & Emily
Yorkshire Marriage indexes for the years: 1888
LILLEY Martha A BACKHOUSE Homar Leeds Registered Building Leeds RB/92/39