Marie, Thank you very much for your information. It requires, as is often the case in Fam. Hist., that I look again as the track I have been going down diverges from yours!
If it works, I will try to add an attachment to this message with photocopies from the church records which I have related to the following information.
I have Mary Ann baptised in St Columba's Church, Parish of Templemore, Derry on the 13th of February 1844. The father is registered as Thomas Nellis and the mother Catherine Logue, Sponsors - John Nellis and Mary Hines. Also in the same record is this MaryAnn's brothers John (1847) and Thomas (1849). In the same record I have the marriage of Thomas Nellis and Catherine Logue - 11th June 1841 Sponsors - John Flynn and M Nellis.
As to your query about Hugh, I have drawn a blank. I wondered whether just Ellen came across to Scotland by herself to marry him, in which case he could have been born in Scotland and, perhaps had met her on a visit to Ireland.
Allister