I need advice! It’s important!

Ok so I have this friend I love her dearly she’s like one of my best friends but she gets on my nerves with something that she does she is a insecure person she has told me this she compares herself to others and thinks she’s fat but she’s not and one day we we’re hanging out and she said I wish I were you have the perfect life which is far from the truth and I’m not but nobody is and she is always copying me or if I say one thing she has to say oh I did that or has to one up me like I just finished my driving part for drivers Ed and she had to compare ours she was like oh I drove to Virginia and all of these things and I’m going to get my permit the 23rd and the 29th and she has to do the same thing and said I’m going to get my permit on the 30th and the 5th so she’s like comparing and if I buy one thing she has to get the same thing and it’s so annoying even my mom has noticed it and I said why does she do this and she’s like she’s jealous of you or something but seriously why would she and she says you’re so skinny I wanna be like you and I just don’t understand why. Advice would be great.