My First go at Portraits

Here is my first go at portraits - off-camera flash, D5100 with 50mm 1.8G ! I am going to get some shoot through umbrellas soon , but looking for some feedback ! The Models are my eldest Daughter and youngest being dolled up for her year 12 formal ( Prom )

I think you'll do well with some umbrellas/reflectors to eliminate shadows. I like the 2nd and 3rd shots the best, the last is a bit stark.