Lots of Bestall records on IGI but be careful as some are submitted and contradict each other. Go to
www.familysearch.org, click 'search tab' fill in Bestall (surname) & Ireland (country). Seems Charlotte Elizabeth Leah Bestall has siblings. Other relatives also there. The newspaper notices belong also connect to the family.
Londonderry Sentinel (index covers 1829-1869):
27 Feb.1847: On the 25th inst., at Urney Church, by the Rev. Mr. Rodgers, George, eldest son of William Law Bestall, Esq., Templelyon, county Wicklow, to Margaret, eldest daughter of Audley Caldwell, Esq., Castletown House, Strabane.
27 Nov.1847: November 13th, at Castletown House, county Tyrone, the lady of George Bestall, Esq., of a daughter.
29 June 1860: June 21, at Forthtown House, Castlederg, Frederick Law, the beloved child of George Bestall, Esq., aged 5 years and 4 months.
27 Sept.1861: September 19, at the Forttown House, Castlederg, Margaret, wife of Mr. George Bestall, aged 34 years.