Looking for Isabella Lambton of Auckland Durham England B 28 9 1745

Isabella Lambton (my gt.gt.gt.grandmother )was born in St Helens,Auckland,Durham,England,daughter of John Lambton and Jane Blackett,married George Applegarth 8/12/1777 at Auckland,St.Andrew,Durham,England.This marriage,George's second,(his first to Ann Douglas in 1759 ),produced four children,Jane, Thomas,George and Robert.Keen to learn or hear from anyone who could possibly advise if Isabella Lambton was an only child ,if not how many siblings did she have and if possible their names ,birth,mariage and death details and any other family information.Feel free to email me direct at tavernside@xtra.co.nz.Cheers for now.Jack Richardson,New Zealand