Diane,
On 1881 census she appears to have a younger brother Albert. On Gro website Elaine gave you there is a birth for Albert Hollingsworth in Ecclesall Bierlow (Sheffield) in 1879, which fits. His mother's maiden name was Shannon.
The censuses, apart from 1881, have never been free online.
Dave

On 1881census she is living with John and Ellen Taylor as their niece in Ashton under lynne, not sure if we are looking at the same person

And, in the same house is Albert Hollingworth, age 2, nephew born Sheffield. Therefore Albert almost certainly Ellen's brother
Dave

He isn't mentioned on the (not very good ) one I looked at. Thanks for that info

From this site:
SHANNON, Ellen (Spinster, age 20, ~, residing at Penistone Rd).
Married Joseph HOLLINGSWORTH, on August 14, 1876, by James Russell (Banns) at
St Philips Church, Shalesmoor. Father's name is John Shannon (Collier).
Married in the presence of J Herring,C Marrison.
Notes: .
HOLLINGSWORTH, Joseph (Widower, age 31, Labourer, residing at Penistone Rd).
Married Ellen SHANNON, on August 14, 1876, by James Russell (Banns) at
St Philips Church, Shalesmoor. Father's name is Joseph Hollingsworth (Farmer).
Married in the presence of J Herring,C Marrison.
Notes: .

This looks like brother Albert

Hollingsworth, Albert (of Highhouse Terr, born ~).
Baptised August 28, 1878, by W K Suart at St John the Baptist Church, Owlerton.
Parents name(s) are Ellen & Joseph (Labourer).
Note:

Another brother ?

Hollingworth, Joseph (of HighHouse Terr, born ~).
Baptised May 8, 1877, by H A Goodwin at St John the Baptist Church, Owlerton.
Parents name(s) are Ellen & Joseph (brewer).
Note: Private

Gro gives birth with mothers maiden name as Shannon 1877 J Quarter in ECCLESALL BIERLOW 09C/333

Possible death Mar 1878 HOLLINGWORTH Joseph 0 Ecclesall Bierlow 9c/181

I'm a little confused as it's Hollingworth without an s and not Hollingsworth though it could be down to how it's been recorded or transcribed

Diane,
Many people could not read or write. It depended on who was writing it down and who was pronouncing it with what accent. You can be sure they are one and the same.
There are at least three possibilities for the Ellen you are looking for.
1. She was illegitimate daughter of Ellen Shannon
2 she was daughter of Joseph and Ellen
3 she was daughter of Joseph and his first wife.
It was not uncommon for birth registrations to be missing. Also it was possible that exact age would not be known by the Aunt and Uncle in the 1881 census,
Dave