You could have two showers. One for your friends and one with family. I've heard of this being done before.
Tradtionally the MOH is supposed to throw it but you don't have to. My MOH who is getting married next year and I"m her MOH is having one thrown by her mom. She wants a bachlorette party and a bridal shower. So I'm taking the party and her mom is taking the shower. Her mom really wants to plan the shower so I"m not going to be mean about it and it's actually easier on me.

So maybe you could do this also. Have your sisters throw the shower and your friend throw a party. or vice versa.

Good Luck!!