Not sure if you'll ever read this because you posted this message a long time ago!
My 2x Great Grandmother was Mary HELY/HEALY. She was born in County Clare in 1835 to Edward HELY/HEALY and Mary McKnight. I don't know if she had any siblings because I've never found any Irish Records that match. Mary came to Australia around 1855/57.
I'm wondering if it's the same Mary as yours?