We are talking two different children here ? I have one 'base-born' (as stated on the Dorset parish records from 17-- something), and the other child was the result of the daughter of one brother getting together with his brother (i.e. her uncle) and producing a child ? I think, from memory, they lived in Brighton ?
(Just thought ... puts a whole new meaning on 'naughty weekend in Brighton', doesn't it !)