Maybe if you show him her shots of these two shows, compared with yours, he will do the honors of firing her for you! Ugh, I know that’s very difficult. Once you get into those situations, it’s hard to get out. But if you approach him with no outward malice toward her and just say look, I know she’s your friend but I have to be honest, we didn’t work well together and I don’t really think any of her shots are that good, can I bring along a different second shooter?
Good luck!