I had a similar case, it might give ideas for more research on this family.
When the parents married, his surname was A but all the children were baptised surname B.
Three of the daughters married using surname B, one had her first child in their home parish where B was her maiden name on the birth certificate, but when she and her sisters moved they all changed to surname A on the children’s birth certs.
When one of the three girls died her mother was the informant and used surname A.
The only reason I could see for all this name changing was a second family with surname A in the same small townland, but that isn’t unusual, so who knows.
I see there is a Doyle as witness on the marriage cert and a Doyle informant on Margaret’s birth, they might be worth investigating if possible.