For me, whilst watching, I did notice she had improved, she seemed to have more control. She held her posture better and a lot of her movements were less frantic than in previous weeks. She has obviously been working hard. The dance actually started out pretty well. Overall, she kept her dance tidier than previously.
But as the dance progressed, she lost some control, and got a little more frantic. She seems to have a habit of just flinging herself into position, and there was one point when she flung herself I thought Ian nearly dropped her. Her main issue I think, is she lacks fluidity and a delicate touch – you can't just fling yourself into your partners arms. She needs more muscular control, she seems to be dancing more from the joints and not using her muscles to control the smoothness of a given motion.
I thought this dance suited her 'jerkiness' of movement, so perhaps that is why I feel she had improved. Will be interesting to see if the improvement carries over into another style of dance.