Isabella was born about 1770.
Marriage details https://www.thegenealogist.co.uk/search/master/?type=person&source=&search_type=person&master_event=Marriages&person_event=&fn=george&phonetic_mode_fn=1&sn=robson&phonetic_mode_sn=1&kw=NORTHUMBERLAND&yr=1780&range=10&search=Search#loadwindow_607474838
https://www.thegenealogist.co.uk/search/master/?type=person&source=&search_type=person&master_event=Births+%26+Baptisms&fn=mary&phonetic_mode_fn=1&sn=robson&phonetic_mode_sn=1&kw=newburn&yr=1801&range=2&search=Search#loadwindow_1493683238
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L > Lee | R > Robson > Isabella (Lee) Robson