Thank you for the replies. John Sharples was the son of a Weaver and needing the consent of parents in 1822 means he must have been a minor and needed permission to marry. So that is very promising.
All marriages except 1 at Christ Church in 1822 were recorded as "with consent of parents" as were majority of marriages in 1821 and 1823. (I only skimmed through 1821 & 1823 marriages so can't vouch for every one.) The curate omitted to score through the printed words in the marriage register "with consent of parents". Therefore the phrase cannot be assumed an indicator of age.
This topic was discussed on RootsChat recently, which is why I checked other weddings at Ainsworth in 1822.
A brother of my 3xGGF married in 1820, aged 26 to a woman of 23, "with consent of parents", like every other couple in their parish that year, according to the marriage register. Contemporary curates at some other churches also neglected to score out the consent phrase for years.
Btw Anne Brothurt, being a widow, needed permission of nobody to marry, even if she was under 21. She was legally able to make her own decisions.