Potty mouth angry so angry

[ODFOx]

She's 15. Speaks to us like dirt. Uses language the like if which has never been used in our house.
I'm at a loss. She's youngest of 5: none of the rest of them were anything like this and just look at us open mouthed when she kicks off. She's sexually active, refused to do any school work during lockdown, is rude, disrespectful and horrid to live with: I'm on eggshells constantly as one minute she's ok and the next screaming obscenities in my face,

Any and all advice welcome. I have no idea how to proceed.

Don’t engage with the anger - certainly don’t rise to it - remove yourself from the room if you struggle with this. Stay calm ask to be spoken to politely, they eventually learn the new rules of getting what they want.