Looking for birth details for my Anne Sayle who shows as the wife of Joseph Quilliam on the 1881 census, as birthplace: PATRICK.

Earlier records show that she was born in 1821 and the only entry I can find on the IGI for that year anywhere in the vicinity is: Anne Sayle baptised 22 July 1821 KIRK RUSHEN.

Would it have been normal practise for the two parishes to be "overlapped" at census time? or for someone to be born in Patrick and baptised in Kirk Rushen.
Thank you in advance.
Marjery