The date you give for Edith Annie is that of her
baptism at Laxey / Church of England which was a
church built in the village centre[ now on the electric
railway station] This was to save a walk of some miles to the rural Lonan parish church. Her birth was
not registered[ not compulsory till 1878]
The date for Edith Irene is her birth [ do you have
certificate ?] She does not seem to have been baptized
in C of E but perhaps at Methodist chapel nearby?