Hi,
I have found this family in 1851,
1851 HO107/1945 f.259 p.11 Bedminster, Somerset
Mill Lane
HUGHES
Mary Ann Head Widow 30 Parish Relief
Louisa Daur 7
Thomas Son 4 All born Bristol
Louisa seems to be the only Louisa HUGHES born in Bristol around 1844 and there is a baptism to fit,
Louisa HUGHES Mar Q 1844 Bristol 11 183
Louisa HUGHES
Christening: 07 Apr 1844, St James, Bristol, Gloucester
Father: Thomas HUGHES
Mother: Mary Ann
This looks possible for Thomas's birth, unfortunately I can't find a baptism,
Thomas HUGHES Dec Q 1846 Bristol 11 161
I realise he seems too old to be 'your' Thomas but people often seem to change ages going through the censuses.
I hope you don't mind me asking but why do you think that Thomas was born in St. Peters Parish?
Regards,
Daisy