Waar wrote...
And she's sleeping over for the next few days, I need a plan. Help me my brothers.
Ok now I want to seriously answer your question, No more fucking around!
You say "Help me my brothers" but the key here is "Help me my sister".
Are you on good terms with your sister? If you are she can help you out. If not then just act nice but be charming and tell her that you think shes cute.
Make sure your feelings get out there.
Hope it works out for you man! :D