The Biographical Database Australia BDA has this.
Eleanor Robinson, daughter of John, Eleanor Robinson; Born 4 Jan 1813 baptized 14 Feb 1813, Registered at St Philip's Church of England Sydney, Cumberland [NSW AUS] [Biog Item No. 300012540
And this a brother
John Robinson, son of John Robinson & Eleanor Robinson, his wife; Born 5 Mar 1811, Baptised 29 Mar 1812, Registered at St Philip's Church of England Sydney, Cumberland [NSW AUS] [Biog Item No. 300012417]
These may be red herrings...
There are two Eleanor's on the Cornwallis which could perhaps be the same person. But in 1806 Eleanor Mcintyre is recorded as living with a soldier William Hamilton and in 1825 she is recorded as married to him. So most likely not your Eleanor. I haven't found a marriage to a John Robinson
1.Eleanor McEntire, Court: Gaol Delivery, Tried: 11 Sep 1799, at Middlesex [MDX ENG], Sentence: 7 years, Arrived per Earl Cornwallis 10 Jun 1801, at Sydney [NSW]; Original Remarks: [Destination] Beyond Seas,. [Biog Item No. 100118613]
2.Eleanor Robinson; Arrived per Earl Cornwallis, Status: FBS (Free by Servitude); Occupation/Residence &c: Housekeeper, [Lives with] P Page [Biog Item No. 110113845]
Also from the 1806 muster
Elinor Robinson; Arrived per Earl Cornwallis, Concubine [Biog Item No. 113311060]
This may be your Eleanor the daughter
Thomas Crumpton, Abode: of the parish [Sackville Reach] [NSW AUS], Signed; & Eleanor Robinson, Abode: of the parish [Sackville Reach] [NSW AUS], Signed X; married 11 Jul 1827 Chapel [NSW AUS], registered St Thomas Church of England Sackville Reach [NSW AUS] by Banns, with consent of Their parents by M D Meares; Witness: Thomas Johnston, of Sackville Reach [NSW AUS], Signed; Witness: James Cotten, of Sackville Reach [NSW AUS], Signed [Biog Item No. 301030008]
You seem to have sorted this out already but maybe these have added something? The BDA is a fantastic resource. You can follow up by arranging to see the records in Sydney I believe.