Answer:
If you mean what activities can you do with your sister, there are heaps. You could:
Go to the movies
Make an obsticle course in your backyard
Draw
Watch a DVD
If she is little, play dolls or barbies
Play a DS or Wii with her and help her on game levels
Bake cookies(my sister's fav thing to do with me)
Have a 'sleepover' together- share a room for the night and set up camp beds (my sisterl loves doing this too)
Read to her
Bead
Teach her to sew
Help her with homework/ school projects
Walk the dog/ wash the dog
Go swimming
Take her shopping if you are old enough
Even just clean up your rooms together is a great way to chat
Write out a 'game list' with everything the two of you will do together that day. My sister loves doing it but I haven't done it in a while.