Cillian Murphy's character's full name is Thomas Michael Shelby; however, the letterhead on his company stationery shows his name incorrectly as Mr. Thomas J. Shelby.
Polly told Ada that her daughter was three years old and her son was five when they were taken away. In Episode #2.1, she said her daughter was turning 18, but then in Episode #2.3, her son Michael said he was only 17.