HELP--Shadows

I have a small studio and im taking pictures of seniors. It works out aside from the horrible shadows. I try to move my lighting around and even switch the umbrellas, but nothing seems to help. Suggestions> Please!

If you can take some advice from an amateur: Have you tried using reflectors? Positioning a reflector on the opposite side of the subject to the main lighting can cancel out deep shadows. If it's head shots you're doing, try getting your subject to hold a piece of white or silver card in their lap out of shot, angled so the light bounces up into their face. You can see the effect before you even take a shot. And it's cheap!