Thank you Barbara & Ricky for your responses. I apologize for the tardy reply from me. The Yorkshire Board gave me information on another side of my family which opened up a whole new generation and many relatives and I've been concentrating on that for the last couple of days.
In gathering the answers to your questions and comparing the data (and if I did the analysis correctly) it appears she was probably born Feb 9-April 2, 1844, not 1845 (I just learned my lesson about fully analyzing all data and reanalyzing each time I get a new piece of information).
To answer your questions:
The marriage certificate to Walter Grantham states married in Lincoln on Feb 9, 1869 and she was 24 years old (born after Feb 9, 1844?)
The 1871 Census taken April 2 in Liverpool (Lancaster County) states she was born in Gainsborough, Lincolnshire, England and was 27 years old (born before April 2, 1844?)
The 1881 Census taken April 3 in Liverpool, Lancashire, states she was born in Gainsborough, Lincolnshire, England and was 35 years old (born abt 1845 or 1846).
The 1920 U.S. Census taken Jan 12 (she was visiting her son) states she was 75 years old (born abt 1844 if born after Jan 12).
I cannot find her in the 1891 Census, though I find her husband, Walter Grantham, and her sons in Bootle (north of Liverpool) but not her. It states Walter was a widower so that's something to figure out since she obviously was not dead. Maybe they divorced or separated? Walter was a Ship Steward and was mostly at sea during their marriage and their sons were 16 and 18 years old in 1891 and the 16 year old was a cook at sea so it doesn't sound like she was involved with the family in 1891.
I still cannot find a birth or christening record for her but I just might not be very good at knowing how to look.
Thanks for all your help. I will follow up on anything you find.
Does anyone know when the 1901 England Census will be available online?
Cathy