Did you check this one:
Eric Jones b. Mar q, 1931, Wigan mmn = Griffiths. So she couldn't be the Edna of 1911
Are we sure that Eric was b. 1931, Wigan
Added - Just found one registered Mar q, 1932 which would fit with the Dec birth on the tree. MMN= Jones.
Need birth cert - Wigan 8c 71