Elizabeth Sinclair-Parents?

[Rhandy]

She married John McBeth/McBeath 1797 Wick, Johns parents James McBeath and Jean? Sinclair. Her son James born 1803, married Ann (Gordina) Innes born 1808 . I cannot narrow down a birth or death for Elizabeth, nor who her parents were. IGI has her marriage as does Scotlands People .There are alot of Elizabeth Sinclairs listed I just don't know which one is mine. Does anyone have any knowledge of this family and could point me in the right direction? All of my great grandmothers family on both sides originate in Caithness.
Any assistance would be greatly appreciated.
Regards Rhandy:confused