Can you see a kitten coming out? She will need to open the sac it's born in and lick the kitten to get it breathing. Then she chews the umbilical cord, and usually eats the placenta. All of this is normal.
I think you may be over empathizing with her and reflecting the fear she feels! If you can, try real hard to be and feel calmness and reassurance for her. A few deep slow breaths might start you off - and it really can help her.