Abnormally attentive readers who are especially well-versed in fourth edition rules might be saying "Hey, wait a minute! Ellen said she was making a tiefling warlock, and warlocks are strikers! With Nicole as the leader and Max 'tanking it', that means Gina should be making a controller!"
If you did remember all that, and did reach that unfathomably pedantic conclusion, before we can continue, I'm going to have to ask that you go give yourself a swirlie in the closest available toilet. Don't lie, you know how to self-administer, go do it, I'll wait here.
Back? Okay. Here's the deal.
Although Lily is strictly only allowing material from the core books for this game, Ellen still managed to stat up a warlock that functions better as a controller - and, because she's Ellen, her build is a more effective controller than most wizards.
And, for those of you who are the polar opposite of our sopping-headed brethren, you who neither know nor give a shit about anything D&D-related, allow me to provide the following metaphor:
The girls are having a potluck. They need a main course, a side dish, a beverage, and a dessert. Ellen bought a bunch of fruit that would normally be used to make a dessert, but then she put it through the juicer, so she's bringing juice, and now Gina has to make a dessert.
Unless she opts not to show up at all, of course, in which case they'll be having a potluck without any dessert - still a good time, but less so.