Help with Wi-Fi connection strength!?

[Adam]

My internet connection is fine, it works top notch. EXCEPT when my sister is home, she is one of those girls who has to be on facebook on her laptop, twitter on her phone and netflix in another tab. I can't sit down on my playstation to play a game of black ops without going through the game frame by frame. Is there ANYTHING I can do to make my PS3 a higher priority or something along those lines? Anything will help.