Update July 2021: Was glutened from one of their smoothies. I've had it a dozen times before so maybe they changed the brand of protein powder? Idk, I will have to ask next time I go in.
I love Prince House and order from them at least twice a week. Their menu format differs from platform to platform, some noting gf options and some not, but if you put "gluten allergy" in the order notes they will make sure for you. They are super nice and have done things like letting me read the ingredients for the protein powder to make sure the smoothies are gf (they are!!)
— Very
— Most/All
— Excellent