How should I handle this

My MIL is an action before analyze type personality. It is so hard to parent my daughters in front of her because every time I have an opportunity, my MIL beats me to it. If we are going somewhere she’s like “ok, you need to go potty before we leave!” And I’m right there, I could say that... it’s my job anyway haha. I just don’t jump out of my skin at a moments notice to say it. I’m more calm. Or if they’re cranky she’s like “ok I think it’s time for a nap! Let’s go have a nap!” And I don’t want to be rude and be like, it’s way too late for them to have a nap now, they’ll never go to sleep tonight... I also don’t want to say that it’s not her place, I’ll decide if they need a nap. Or if my girls get in a fight, and I’m trying to resolve the situation and get them to talk it out peacefully, she’s always RIGHT there talking over me saying “____ you need to say sorry to ____... come on, say sorry! Say sorry to _____!” Like in the midst of them screaming, in tantrum mode, and me trying to calm them. And it’s so hard for me to concentrate on resolving the situation and taking advantage of a teaching moment, and it’s so hard for my girls to focus on me. They don’t know where to look. How should I handle it? We go over her house once a week and every time it is sooo hard to handle! I end up getting overwhelmed and pissy