Why is my best friend so stupid?

Basically, I have this girl friend. She’s been my friend for 5 years off and on. We’ve always split because (she says) of my boyfriends, they hated her, thought she was a lying manipulative b***h and they would make me not hang out with her. Now I’m friends with her again, have been for 8 months or so and honestly she drives me crazy. She constantly lies to me about “great” things happening in her life. Problem is she is a HORRIBLE liar, awful, and I catch her in almost every single lie she spits at me. Her stories just don’t add up at all.

Now, I try and tell her without actually telling her she’s a huge liar and I know it. It’s just not working out for me. She denies EVERYTHING and her lies just keep getting bigger and bigger.

Honestly I enjoy her friendship, she’s like a sister to me, but how can I get her to stop making up this crazy imaginary life. How can I get her to realize that she doesn’t have to try so damn hard to impress me and that I’m not impressed!