ask her (or leave her a letter if she won't engage).
How does she think her teacher would feel if DD said to her "you are a f*ing idiot bitch, I hate you, I wish you were dead" ?
How does she think DD would feel if her teacher said to her "you are a f*ing idiot bitch, I hate you, I wish you were dead" ?
How does she think DD would feel if the woman at the shop said to her "you are a f*ing idiot bitch, I hate you, I wish you were dead" ?
How does she think the woman at the shop would feel if DD said to her "you are a f*ing idiot bitch, I hate you, I wish you were dead" ?
How does she think DD would feel if you said to her ""you are a f*ing idiot bitch, I hate you, I wish you were dead" ?
How's does DD think you feel when she says that to you ?
It isn't an effective way to talk to anyone. If she has a problem, she needs to talk to you in a fair and rational way and between you, you can try and come to a workable arrangement that is fair to you both.