Thank you very much for the link - I had looked on family search but not found it!
I now know that Mary Woolley, my great great great grandmother, was baptised in Aldford on 12 Jul 1812 and that her parents were George and Ann.
On the 1841 census, after Mary had been married there was a, 'William Woolley 15 Carver & Guilder' living -or staying - with the family. The William I have found on the site (with the same parents and birthplace) was baptised in Dec 1821 making him 19 at the time of the census. I think ages were rounded down to the nearest 5 in 1841 so this is probably one of her brothers.
Her siblings, all born in Aldford to George and Mary Woolley, seem to have been:
Martha 17 May 1807
Ann 8th July 1810
George 10 Jul 1814
Catherine 6 Jul 1817
Sarah 30 May 1819
William 23 Dec 1821
Frances 2 May 1824
There was a witness called Martha Wooley at Mary's marriage to Edward Jones in 1831 - this was probably the sister born in 1807.
I've also found a Hannah Woolley who may be part of the same family (same parents names, roughly same area) - but she was baptised on 15th Sep 1826 at St. Mary's-on-the-Hill, Chester. I'll have to try to locate censuses with them on to see if it's the same family!
Thanks