From the details posted by Neale earlier, which included the marriage register entry for Thomas and Caroline's marriage with fathers' names, below is I think the baptism entry for Thomas (23 May 1827 at St Anne, Limehouse, Tower Hamlets).
Possible siblings include the children below. These are baptisms at St Anne, Limehouse, Tower Hamlets, except for Peter John which took place at St Dunstan and All Saints, Stepney High Street, Stepney):
1821 Julia Anna...late marriage to a William Brooks in 1868. She died in 1871.
1822 Peter John...died 1825
1825 Lucinda
1825 Eliza Mary
1827 Peter Thomas (as above)
1830 James
There is also a marriage in 1860 in Poplar, Tower Hamlets for a Mirian Mitchell to a John Samuel Payne. Her father is showing as Thomas Peter Mitchell, mariner. Caroline Mitchell looks to be one of the witnesses.
Monica
