Hi Susan
not found the marriage, but found a lot of census info and it seems that Rosetta was there first child as in 1871 she is with her grandparents in Suffolk and still with them in 1881 in Lancashire.
In 1861 John is still single aged 19 and at home with parents but by 1871 he is re married to a Maria who is 10 years younger than him.
if you want any full deatails from the census, please send me a personal message.
Janway