Which lens to use with my studiowork?

I just started a small studio in my garage ( 4x3m).  I thought that the best lens for studiowork (  faces, half body) should be in the range of lets say 80-120mm ( FF equiv. ). I have enough distance of the subject than. I used my Sony 55-200

After my first shoot with my daughter she said to me: " it looks like i am a little blownup in my face.....:-( " ( most shots on 100mm).

I need another lens thats for sure ...what do you recommend. The distance of the subject is about 2,5 m i will do faces and half body shots.