Other mistake: When Polly tells Ada about her two children being taken from her, she says Michael was 5 and "Sally" was 3. When she goes to the seance she says her daughter would be 18, but shortly after that Tommy finds Michael and he is 17. Also, when Tommy tells Polly that he found the records on her children, the daughter's name changes to "Anna."
Suggested correction: The age difference could definitely be the case. Depending on the timing, she might be 18 years 9 months and he 17 years 1 month; in a month, Sally would turn 19 while Michael would still be 17. About the names: Since the children were taken from her, it would make sense that they changed the girl's name from Sally to Anna (I'm not sure how Polly reacted). Because Michael was already five, a name change wouldn't have been necessary - he was old enough to remember his original name.
Episode #1.1 - S1-E1
Factual error: Ada is watching a movie and when asked "tell me the man's name" says "Rudolph Valentino." Valentino was largely unknown in 1919, only appearing in bit parts. She is also eating popcorn. This was not done in movie theaters until the 1930, unless you brought your own. Only street vendors sold popcorn.
Suggested correction: This is from episodes #1.2 and two separate mistakes. But being "largely unknown" doesn't mean she couldn't know his name. And who's to say she didn't buy the popcorn from a street vendor? You don't see others eating popcorn, so there's no suggestion she bought it there.
He used the name Rudolph Valentino for the first time in 1921.
That's not true since he was credited as Rudolph as early as 1917.
