Without seeing your players, it's hard to pinpoint where the problem is, be it hands, arms or feet, but I see a lot of players who still field ground balls with 1 hand down. I haven't yet, but I want to put their wrists together with a thick rubber band so they can't separate them. I tell my team 50 times a practice, "wrists together".
I also still see big sweeping arm motions when throwing. They bring the ball down by their waist, making that old school "big circle" before bringing the arm forward when throwing. I like the saying "palm together,palms apart". after we field the ball and it is secured in our throwing hand our palms are together. From that position, our palms should move strait apart, glove forward, ball back, then throwin motion starts.
with the feet, I just continue to work on them moving through the ball, without stopping, pausing, etc. I like to start with the ball lying on the ground. They must go toward the ball. It will not go to them. That gets them in the habit of moving forward through the ball. Some girls just have slow feet and speed/agility work can help with that. But sometimes the old saying is true...You can't make chicken salad out of chickens**t. Good luck