Heeelp with lighting / posing

I had a quick play this afternoon to try to get some nice family portraits before my little one gets past the newborn look. Anyway these were taken using an SB800 fired through a white umbrella (right) with a window for fill (left) I think I lost some fill light at one stage so probably should have gone for a reflector.
This was my test shot & I was pretty happy with this so left my settings at 1/250 @ f/4 with Tamron 90mm
but some pics just didn't seem right, maybe I should have stopped down another stop or 2
maybe because I chopped arms off, I was using a white sheet as a backdrop, I might run an iron over it next time.
Maybe I should be facing people more into the light instead of back at the camera
I like this one though
comments appreciated
This was my test shot & I was pretty happy with this so left my settings at 1/250 @ f/4 with Tamron 90mm

but some pics just didn't seem right, maybe I should have stopped down another stop or 2

maybe because I chopped arms off, I was using a white sheet as a backdrop, I might run an iron over it next time.

Maybe I should be facing people more into the light instead of back at the camera
I like this one though

comments appreciated