Are these symptoms of autism?

A few years ago I wrote on here about my niece. I’m a calm and easy going person and it takes a lot for me to lose patience but when it comes to my niece (not just me but everyone else) she sure knew a way to make our blood boil.

Ever since she was little (she is 14 now) she would always randomly scream and blurt out random words, sing loud and horribly on purpose, run around and scream, etc. basically use very loud outdoor voices indoors. She would constantly poke me and everyone, get in people’s faces even though we ask her nicely to stop. She’ll just keep doing it and ask why why why.

She is extremely smart and she knows it. She has a huge ego and think she’s the best, smartest, and does no wrong. She was recently diagnosed with autism and depression. Since she’s been on medication and she’s been happier but I feel like her actions have gotten worse and she just blames it on autism. When she does something that makes people angry she laughs and thinks it’s hilarious. She has a habit of spitting and she spat on my car and laughed when I got upset. Then she blamed it on autism and said she doesn’t have empathy.

She refuses to take a bath for days. She is moving in with us and I feel bad for saying but I never had anyone make me so angry and I can’t imagine living with her. I want to move out. Her mom (my sister) and her are moving in because she broke up with her boyfriend. I have no peace and quiet. The other day she kept knocking on the door as I was showering and wouldn’t go away. She just sat outside the door rambling on about nothing and singing.

Then she proceeded to sit outside my door as I told her I can’t play a card game and she kept asking why why why. She kept knocking on my door at night and just sat out there for an hour talking to me as if I was paying attention even though I told her I need to wake up early for work.