How to tell your best friend?

Please don't judge or anything just hear me out and give me some advice. so my best friend has two daughters, one is 7 and the other is 3. I know she's going through terrible 3s but oh my gosh this little girl does not listen to anyone!!!! She screams at the top of her lungs in the middle of stores, runs wild, and is really rude to people in stores. And my friend doesn't seem to think she's that bad. She usually just lets her do whatever she wants and when people say something my friend goes off on them. I love these little girls but oh my god I refuse to go to any stores with her anymore if she has her kids. Please how do I tell her, her kids are monsters in public without her getting mad at me? Sorry long rant.