How Do I Get My Friend To Admit Why She's Lying To Me?

I have a friend. We've been friends for a few years, and I'm really getting tired of the dishonesty. I mean, she's lying about really dumb stuff, like 'my dad did take me to your pool party, but we went to the wrong place,' and makes excuses all the time for her odd, sometimes even a bit pushy behavior. I mean, she's a good friend. I can trust her with anything. But she's gotten a bit snotty, a little offensive, even. I mean, who asks, "Hey, will you become late to your own party just so you can pick me up, take me with you, stop at the Dollar Store for me, and let me borrow your swim suit?" In fact, she doesn't even ask for stuff. She'll get really pushy and say stuff like 'I need you to drive me here,' and 'Either way, you're letting me borrow one of these things.' I'm tired of it. What should I do?