I know one of my O'Sullivan's married a Daly. Jerry Daly married Norah O'Sullivan in 1890 in Ireland. They had one child Hannah Maria Daly. This knowledge came to me from an Aunt I had in Dublin in a letter received 2008. She wrote:
Nora married Jerry Daly 1890 one surviving child Hannah Maria- Hannah married Batt O'Connor about 1923. They had five children -
Jeremiah who emigrated to England and supposedly to Australia;
Denis married in home place in Ballyfinane to Carmel MacEllistrim. They have three children - Betty married in Dublin; Nora married in Kilflynn and Norah Kerry to MacElligott. And another girl Siobhan died young.
Doesn't look like that is of any help but I will post it anyway. Carol