Hi Anne.
At the time of the wedding (April 1896) both bride and groom appear to be living at the same address, 5 Burrells Lane, Glasgow. Mary Ann, aged 20, is listed as a sewing machinist. Her parents are Patrick Kelly (Dock Labourer) and Ellen Kelly (nee Reilly).
I obtained the details above by using the information on the 1901 census you provided, where she is named as ‘Mary McV Kelly’, so when I did a search for her marriage I entered the husband’s surname as a wildcard (McV*) and her name as Mary Ann Kelly. The three grandchildren on the 1901 census also have the name ‘McV Kelly’ and the eldest would have been born around 1895/96. Her marital status in 1901 says she is a widow, but I have to say, it does seem strange that she is showing both her marriage and maiden name for herself and her children on the census return. Do you know if it was likely/acceptable, back then, for a woman to revert back to her maiden name if deserted, by her husband, rather than widowed?
I don't have a copy yet of my grandmother Alice’s Birth Certificate, but I presume it would just say the same as the Registration of Birth which shows Mary Ann as just Kelly, and until I saw the 1901 census I had always presumed her to be single. Perhaps, because Alice had a different father, she didn’t feel it appropriate to give her the name of her (presumably) dead husband when he had no connection to her (and especially if she intended not to keep her). Who knows what ‘logic’ goes through peoples minds when completing census and registration forms, lol?!