Well I found this and I think these are her parents and her potential son Peter Michael Russell.
http://www.jbhall.freeservers.com/dromin_inscriptions_01.htmGaynor (R3 12) (Russell)
Erected by Owen J. Gaynor Peabody Mass. U.S.A. in memory of his beloved father Owen Gaynor,
Dromin, who died 8th May 1871, aged 55 years, also his beloved mother Mary Gaynor, who died 29th Dec 1883, aged 63 years.
Also his loved nephew Peter M. Russell of Dundalk who died 21st July 1893 aged 16 years.
May they rest in peace.
I also was sent by private message details of a family in Dunleer Parish around Dromin.
Marriage Mary O'Neil Eugene Gainer 16 Feb 1849 Mooremount.
Baptisms
Mary Gainer 27 April 1850 Ward's Hill
James Gainer 1 May 1852 Halfpenny's Town
John Gainer 23 Aug 1854 Ward's Hill
Mary Gainer 10 May 1857 Ward's Hill
All baptisms have Owen Gainer as father and some variety of Mary O'Neil as mother.
Have found the Owen Gaynor who put up the gravestone in American census' but no baptism for him yet. Found a tree on geni tried to make contact, to no avail but hey ho.
Thought I'd include this incase anyone else is or will be looking in the future and to give give me chance to say thank you for all your help and for taking an interest.