Adelaide Ward was definately born 11 May 1899 in Yorkshire
In Yorkshire - not necessarily Leeds?.
So the 1899
York birth looks as if it is her, and the 1901
Leeds census that I found also. But it seems you have that already. (Clifton Street, Leeds)
You mention an address at time of marriage - the marriage I found was in York Reg District - so the Union Street you refer is in York?
If you have the marriage cert it will give George's father's name and occuption, as well as George's occupation, all of which might help find George earlier. Also as Nanny Jan has mentioned, George's age.