Thank you very much for all of your responses. Today I've been rather puzzled - had a phone call with my Grandma to speak about Sadie, she remembers Sadie being "quite a bit" older than Eddie (Edward) when they married, and my Mum thinks she was in her 40s when Alan (her Dad) was born. I said I'd found 'Sarah Lowe' dying in Barton in 1974, with the birthday as 18 Nov 1919 - my Grandma said this was definitely her. Now the marriage certificate says Edward Lowe was 23 and next to Sadie Monaghan I believed it to be 23 also, but now my Grandma believes it says 33. Either way - if 33 in 1945, she would have been born in 1912, if she was 23 she would have been born in 1922... I've searched ScotlandsPeople for a Sarah and a Sadie Monaghan between 1911 and 1914 and there is no one with the father of William Monaghan, so I'm extremely confused at the moment. I'm about to search further back assuming she may have been in her 40s and see what comes up if not then perhaps 1919 Sadie/Sarah is her and for some reason there has been confusing in records with her birth year. She also told me that she had a brother 'Alan/Alen Monaghan' who had come to Urmston/Davyhulme with her, who married a Pauline and they had twins, I'm about to set out to look into him now, and initially before I was puzzled about birth year - if the 1919 Sarah is her then she must have gone with her father's family if she has a brother named Alan/Alen?
Sorry for the long winded message, this just got a bit confusing today! Will post a photograph of the marriage certificate and see what you think on the written ages if possible