Re: Maryanne Qua (1870) and descendants
I have a Samuel Qua from Armagh county, born 1829, died in Paris, Ontario, Canada sometime after 1881. I assume he's related somehow to the Quas in your list.
He was the father of George Qua (my great-grandfather), who fathered my grandmother, Ruth Qua, both also of Paris. She married a Knowles.