it's 19th century! So...jaenne wanted to see you. Even though she is your biggest enemy, she found out that..you like Vanitas. But she Loves him..too. he makes her feel loved, cared for.. something she can't describe. But she just know that she needs to ""consummate"" their love (she says) when she sees him. But she found out you like Vanitas.. and As long as she wanted to strangle you for that, she just send you a letter that said that she needs to see you as soon as possible