Good evening Suz
1851 mother is Mary Ann
1861 mother is margret
I have found a marriage in Merthyr in Sept qtr 1855 between John Prothero and Margaret Williams
Maybe that is the solution to the puzzle
A wife per decade - thats pretty good going!!!
So hows about John marries Mary ann Pritchard who is pregnant with James
They have John P junior
They move to Merthy and lodge with friends - for what ever reason he is no longer with Mary A and in 1855 marries Margaret
By 1871 he is fed up with Her

and marries Ann - unfortunately I can't find a record for that marriage though.

Liz