I guess this is the record you have for Rachell.
Rachel Tomkins
Baptism Date: 20 Nov 1740-1741
Baptism Place: St Peter and St Paul, Harlington, Hillingdon, Middlesex
Father: James Tomkins
Mother: Mary Tomkins
These for William?
Wm Langton Baptism 6 May 1730 St James, Piccadilly (St James, Westminster) Wm,Mary
William Langton Baptism 18 May 1735 Saint Giles in the Fields, Saint Giles High Street, Holborn, Camden Wm,Mary
However I note one tree has his parents as John Langthorn and Mary Shaw but no birth date for William?
The records at Harlington are on Ancestry, I have had a quick scan of baptisms 1730 – 1740 I do not see William being baptised there.
William Langthorn Burial 28 Feb 1787 St Peter and St Paul, Harlington, Hillingdon, Middlesex. He is noted as a Labourer but no age recorded.
The problem with all of the above baptism’s is I do not see a link to Williams children’s names, I find this unusual for the period?
Colin