Hi Pat,
I've looked on my tree and indeed Ellen Farrelly (nee Burke) is a sister of my great grandfather's 1st Wife, Mary Burke. The only info I have on them though is that she married Patrick Farrelly and had children Mary Ann Farrelly (1900), Ellen (1901), Alice (1903) and Patrick M (1906). I can do some further research here if you wish and if you send me your e-mail address I can give you a link to my tree. I will try to find out more on the Farrelly side for you but would be interested to hear any info you have on the Brady side also if you wouldn't mind.
Fran