Thanks again for going above and beyond1 I have been scouring that register and collecting all the McGugans I come across!!
You were right about Malcolm's date of birth it was 15th!
Nancy's record, I found her death. She died as a baby of 4 months old. Also the records for Christina seem to be duplicates of each other and 2 are placed in the wrong year. The one states that she was born in 1864 yet it's found in the 1863 book.
I'll look up the other researcher you mentioned! Thanks so much!!