After the Battle of Flodden Margaret sobs over the body of her husband James. This never happened. The battlefield was filled with dead bodies and his body was never identified. There were rumors that he actually survived the battle and when divorcing her second husband Angus Douglas she used the rumors as a reason why her second marriage was not valid.
Catherine talks about their cousin Charles and his father Maximillian. The relationships are all wrong though. Charles was her nephew (the son of her sister Joanna) and Maximillian was his grandfather (the father of his father)
Henry ask Thomas Boleyn for his daughters Mary and Anne to be at court to be lady's for Cathrine and are seen over the years between then and when Catherine leaves. However when Henry asked Anne and Mary were on the continent In the court of Margaret of Austria and later Princess Mary during her marriage to Louis XII. They did not return to England until 1520.
There are several mistakes in regard to the battles. Before Catherine rides to Scotland she finds out about Henry's win at the Battle of the Spurs. However there was about a month between the two and very unlikely that she would have found out that fast. Henry also did not get back from France until a month after the Battle of Flodden so he was not there when Catherine gave birth several days after Flodden.
The Battle of Flodden supposedly takes place less than a year after the death of Catherine and Henry's firstborn son Henry, Duke of Cornwall died. He however died in early 1511 and the battle of Flooden happened in September of 1513 more than 2 years later.