Ellen had children 1781 to 1788, that all died in infancy. However it is unlikely she was much over 40 when having John, so probably born about 1745, and married 1762, when 21.
Possible Whittle, Heapey
Name: Ellen Howarth
Baptism Date: 26 May 1745
Parish: Heapey, Lancashire, England
Father's name: John Howarth
Mother's name: Mary Howarth
Register Type: Parish Register
Reference Number: PR 2908/1/4
Ellen dr. of John & Mary Howarth of Whittle
Just one BIG problem: "Ellen D. of John Howarth of Whittle" (North of Rivington) was Buried 22 October 1745.
Possibly from Blackburn, Dau of George and Ellen, bap. 28 Jun 1741. This seems a little early for the late births, but there is one thing going for it. George and Ellen had Ann 2 years later, so Elllen and Ann are sisters.
Also possible Livesey, Blackburn dau og George (who also has a daughter Ann)
Name: Ellen Howarth
Baptism Date: 28 Jun 1741
Parish: Blackburn, Lancashire, England
Father's name: George Howarth
Mother's name: Ellen Howarth
Register Type: Bishops Transcripts
Reference Number: Drb 2/6a