querty on Family Tree Circles

I am looking for any surviving relatives of PATRICK JOSEPH BRENNAN born approx 1888/1889 in Ireland.My only information is that his father PATRICK BRENNAN was shown as a farmer on his birth certificate, and a witness was a THOMAS RABBIT.
I know he was baptised as a Catholic in TUAM CATHEDRAL as I have seen the Baptism Cert as a child. He also he got married in 1915 in Lancashire ENGLAND and gave his age as 26 (hence the 1889 dates) he died in 1957 again his age was 68 again a date of 1889 by subtraction.
I have a birth certificate from the Irish Registary Office in Dublin that gives his mother as an ANNE WALSH but the "BRENNAN FAMILY HISTORY SITE FOR TUAM" gives a family tree with his Mother named as MARY WARD so you can see my confusion??.
Any leads would be followed so please give any links you may feel would help.

BERNARD