How well do your characters adjust to circumstances and/or other characters as they change? Jenny becomes more adept at magic and more aware of what her mother’s up to and Eileen is aware this is not necessarily a good thing as what she used to get away with, she can’t now. How your characters react to and handle changes reveals a great deal about them...
Also think about what reaction you want to generate in your reader and check that those likely reactions are what you want to achieve. Are the sparks your characters generate off each other the ones you meant to write? Or are your people surprising you by their reactions (if so, how? Do you need to look at how you've portrayed them initially? Or is the surprise a one-off thing due to the situation you've put them in but you have found out this is the way they react under stress?).
Reactions are good. It shows there is life in your story, it is an active, moving story. Nobody stays still in life for long. Your characters shouldn't either.