Hello again Michaal
I do not think your Jane does belong to this family. These are George and Mary's children
George Garret married Mary Dehaye 15 Feb 1801 St Matthews Bethnal Green
Phoebe Garrett baptised 19 Apr 1801 St Matthew, Bethnal Green
George Garrett baptised 9 Oct 1803 St Matthew, Bethnal Green
George Garrett baptised 31 Aug 1806 St Matthew, Bethnal Green
Mary Ann Garrett baptised Mar 1809 St Matthew, Bethnal Green
Selena Garret baptised 16 Jul 1815 St Matthew, Bethnal Green
Note though ancestry has transcribed her name as 'Martha' the actual marriage entry correctly reads Mary.
Jane seems to belong instead to this couple:
George Garrett and Martha Garrett married 21 May 1794 St Andrew Holborn
George William Garratt baptised 5 Jan 1794 St Andrew, Holborn
Jane Garrett baptised 29 May 1803 St Andrew, Holborn
Joseph Garrett baptised 29 May 1803 St Andrew, Holborn
Eleanor Garrett baptised 3 Feb 1805 St Andrew, Holborn
Henry Garratt baptised 12 Apr 1807 St Andrew, Holborn
Ann Garrett baptised 17 Sep 1809 St Andrew, Holborn
George James Garrett baptised 13 Oct 1811 St Andrew, Holborn
Holborn is in West Central London, quite a way from Bethnal Green which is in the East End. This also matches up with Jane's marriage in Bloomsbury which is a parish directly neighbouring Holborn.