Family Member Greenhalgh Billingham

could anyone answer a question that is stumping us, we have an ancestor John Greenhalgh Billingham baptised 12 october 1828 St Peters Bolton Le Moors father was JNO Billingham and Mother Ellen, we cannot find anything for her other than the 1841 census where she was living alone son at boarding school, we are wondering if she could have been Ellen Greenhalgh but all we have to go on is her birth in 1791 cannot find a marriage for her or John, do not know where to look now to find out who she was, any ideas would be most welcome.

Many thanks

Susan