Eugene Onegin is a novel in verse, by the great Russian poet Alexander Pushkin. The main characters are Eugene Onegin, a young and bored man, and Tatiana, an even younger girl who falls in love with Onegin.
Onegin is said to be in his twenties during the main events of the novel, but I don't actually remember how old Tatiana was.
Do we know Tatiana's age, either from the novel or other sources?
This question was prompted by a guy on the Internet, who claimed that Onegin was 21, and Tatiana was 13, at the time she writes the letter. This is, of course, absurd.