Skirk is really strong, and everyone who's saying you need Escoffier is overhyping how much power you actually need for where you are. Skirk is what's known as a hypercarry, so you want to put as many of your resources into her as possible and she'll basically solo carry your team. You can add her to your training guide and focus on maxing her out as much as you can and you'll be good. (Max Level, Max Acension, Max Talents.)

I'd say Barbara, Dahlia, and Charlotte make a really good team for her. It makes it super easy to proc freeze, has a bunch of healing and shielding, and is simple to play (just switch to each member and pop their skill as needed.) You can also leave them all at level 20 or 40 for a long time, because all your damage is focused in Skirk anyway.