Lydia Maria hasn't led anywhere yet, but the search has brought up the following baptism:-
21 Nov 1822 Jane dr of Michael & Elizabeth OLLIFFE in Ballymodan
Ballymodan appears to include Bandon, which is where George married Thomasina GOOD in 1851, so Jane must surely be related in some way to Robert (1822) and George (1826), but, how? I assume that Michael would have been born ca 1800, so, could he be a brother of Robert (c 1805)?