Firstly, you need to stop the current lap times from lowering further, if you succeed in beating her lap-times now, she will just come back and beat you again, we have to deal with her.

A hit-person is the same as a hit-man, but it isn't sexist, because sexism is wrong!
You need to use our secret website to find a hit-person in your area,
follow our super secret 100% secure link -> ebay.com

type into the search bar "illegal hit-person service in my area"
I can't tell you which hit-person to hire, but try to hire one who isn't sexist, because sexism is wrong!

-WARNING- When giving the details of the hit, remember to give them your sister's name, not yours!!

You can't beat her lap times in prison, so after she's gone, tell everyone how much you miss her and how it must have been an accident because nobody cares about lap-times that much.

Use our secret link once more to hire somebody else's little sister.
As always, price is the only predictor of quality,
so hire only the most expensive pro gamer to fake your times.

Then you just wait and watch your lap-times fall, it wont be long before you can show these amazing times to your sister and make her dead jealous!

Let me know how you get on, any questions? just ask :)