A bit of something or nothing.
In 1853 Patrick Brown b Ireland marred Catherine Hegarty b Liverpool in Bangor
In 1861 they in Mold with daughter Margaret registered 1854 Holywell .
In 1871 they are in Bangor, Margaret is 17.
1881 and Margaret is missing, but there is a son James 12 b Bangor .
James is with the family till 1911, he married in 1912 and died in 1934 aged 63, so born 1871
A James Brown was registered June qtr 1871 Bangor mmn Brown.
Could James be the illigitmate son of Margaret Brown, and Patrick and Catherine really his grandparents.
The birth registration for Mary Brown hasn't been found for sure, the only clue is she says she was born in Bangor and her father was James Brown.
It's possible that if she was born c 1890 / 1891 that James b 1871 was old enough to be her father.
The only drawback is that this Brown family seemed to quite settled and employed .
This doesn't sit right with Mary being destitute, but it depends on her mothers circumstances.
This all must be taken with a pinch of salt but .......