She's nothing special outside of abusing multi-windows in raids for Paralyze lock.
With SSR Cybele and Titania, you can basically use whoever you want though. It's not like your gold books are a limited resource, so why not? You should at the very least level every character to max level anyway.
Miracle Ticket questions are pointless until Miracle Ticket is upon us. Still, there's two kinds of Fire teams - ones with Svarog, and ones without. Since you have Belial, your course of action should be clear.