The McIlhaggo-Aiken Problem

My correspondent about Islandmagee has set me a problem. Our clan member who farmed in Portmuck was Samuel McIlhaggo. He left a Will in which he makes one of his three sons-in-law Mathew Aikin (or Aiken) his Executor and indeed a beneficiary. Unfortunately the original copy of the Will is damaged and many words are indecipherable. These include the name of his granddaughter who married a Mr. Noy or Hoy. My correspondent tells me that Mathew Aiken who is on his family tree married an Eliza Brennan. He gives their respective dates as 1758-1830 and 1774-1838. He also says their daughter Mary, born 1795 married a Mr Hoy! I am wondering if Mathew married twice, first to Samuel's daughter and then to Elizabeth Brennan. This might be indicated by the fact that Eliza was 16 years younger than Mathew. I suppose another possibility is that Eliza was Samuel McIlhaggo's daughter and that she had been married first to a Mr. Brennan and that she married Mathew Aiken as a widow. A third, but I think remote possibility, is that Eliza's middle name was Brennan. Unfortunately Samuel's Will doesn't give us her name, but it does make quite clear that Mathew was his son-in-law.

There is an additional reason to think that Mathew Aiken may have been married twice. On the Aiken family tree Eliza Aiken (nee Brennan) had a daughter Mary who married a Mr. Hoy. The (1818) Will of Samuel McIlhaggo named a son-in-law Mathew Aikin (or Aiken) and a granddaughter Mary whose son John appeared to be fathered by a Mr. Noy (Hoy?) otherwise Napier. However no son John appears on the Aiken family tree, so maybe there were two Marys, one the daughter of Eliza Aiken (nee Brennan), one the daughter of the daughter of Samuel McIlhaggo. She (ie the second Mary's mother) was possibly a first wife of Mathew Aiken or else the wife of one of the other two sons-in-law named in the Will. There is of course a further possibility that she was and remained unmarried and had a child by Mr. Noy/Hoy. We need some more evidence, but where will it come from?