I have links to the Doyle side of this family. Christina was the daughter of Thomas Doyle and Mary Bennett and was born in 1890.
Thomas was the son of William Doyle and Ellen Callan although I haven't been able to locate a birth cert for him. He was born in around 1860 possibly in Monaghan and died in January 1947.
Even though I think Ellen Callan was from Monaghan and some of their children were born in that area, I suspect William Doyle was from Ballsbridge and the family goes back another generation or so in the Ballsbridge area to Gregory Doyle and Christina Loftus.
My Dad grew up in the area and says there were loads of Doyle families-looking now it seems he might be related to quite a few of them!