Hi Katzpurr,
Welcome to Rootschat

For our reference, William Henry and the 6 following siblings must be these? So, showing consistency with the mms.
ISSUE: 1 William Henry EDMUNDS 1864, mms RICKETS(Bangor)
2 Grace 1867, mms RECKETS (Bangor)
3 Annie 1870, mms RICKETS (Bangor)
4 Sarah 1872, mms RICKETS (Bangor)
5 Jane 1875, mms RICKETS (Bangor)
6 Ellen 1878, mms RICKETS (Bangor)
7 Thomas 1881, mms RICKETS (Bangor)
Ann's ages & POB's at Census and at Death:
Ann: 1871 - b Penmorfa, age 33 (b abt 1838)
Ann: 1881 - b Llanllechid - aged 47 (b abt 1832) son Thomas is days old.
Anne: 1891 - Dolbenmaen - age 53 (b abt 1838)
Ann: 1901 - Llanllechid,- age 63 (b abt 1838)
Anne: 1911 - Penymorfa- age 73 (b abt 1838)
Ann: 1919 - Reg Bangor 1919, age 82 (b abt 1837)
The 1901 Census, her age is a little difficult to make out - but I do believe it is 63 - the little tag on top of the digit - and definitely not 68 or 60.
That would make the 1881 Census the exception - where her age is clearly enumerated as 47. However - her infant son is only 2 days old. It's not unheard of to be giving birth at 47, but I'd lay bets that in 1881 she is probably is about 43.
Overall, her yob is consistently abt 1838.
Her place of birth - my inclination would be to zero in on the smallest place, Dolbenmaen - which is connected to larger Parish/Rectory of Penmorfa. Both are covered by the Registration district of Ffestiniog - and there is connection to Merionethshire too:
http://www.genuki.org.uk/big/wal/CAE/DolBenMaenhttp://www.genuki.org.uk/big/wal/CAE/Penmorfahttp://archiver.rootsweb.ancestry.com/th/read/WLS-CAERNARFONSHIRE/2004-01/1073152914I agree, she could have been born RICKET, perhaps illegitimately, perhaps not, perhaps just prior to civil registration and her mother may have married or remarried to a man whose name Ann took.
She may have married prior to Henry- she was possibly 26 yrs old in 1864 when her first known child with him was born - and if that's the case it could be a double puzzle - she may have married 1st under a stepfather's name and then married 2nd to Henry under a first, late husbands name.
But then......there is lack of evidence of Henry EDMUNDS marrying anyway. If she was married prior, and that husband didn't actually die, that could be the reason there.....there's no ambiguity about Henry's name is there?
Cheers
AMBLY