Scotland's People has just two recorded baptisms of children to Alexander Bremner and Isobel More (using name variants for him and is* m*r* for her). John in 1774 and an unnamed child in 1789.
There are no recorded children of Alexander Bremner (using name variants) without a mother's name in Wick betwen 1750 and 1800.
This means that the baptism records of Anne and any other siblings, if they ever existed, have almost certainly not survived.
I see that there is a death of a James Bremner, mother's maiden surname More, in Wick in 1859, aged 81. Presumably a brother of Anne, John and the unnamed child.