Thank you for that.
A bit late for my family - unless I find another descendent or two. But I've saved a copy and stashed it in the appropriate file.
The birth registration of Mary, Senior, states under Children of Deceased - Living Ann 57 years, one male and two females deceased.
One would imagine that if Ann included her brother who died in the US, she would have also included any siblings who died in Ireland. Ann gave her mother's age as 104 years which would have made her about 47 at the time of Ann's birth. A bit old perhaps, but not beyond the realms of possibility.