Oh I can SO relate, my sister is almost 16 and shes worse then my kids when she sleeps over!glad you figured it out! I have a carpet cleaner that gets out pen marks on our microfiber couches. It doesn't appear gone until the next day, but it works.
(vent: the pen marks are NOT from my children. they are from grown women who somehow get their pens on my couch! grrr!)