I would suggest an email to your L before you send any message regarding the insurance. Make sure you know what you are required to do and what you are likely to win in court. Personally, I agree that she SHOULD be required to reimburse you but I don't think it's likely that you'll win that. No need to add more emotional fuel to her fire if you can't win anyway.
I like NB's thinking but now might now be the time to employ it. However, you should be keeping the record as she indicated. Just in case...
BTW- I hope that you've gotten a solid agreement in place regarding school. Based on her past behavior, I can see her coming after you for school expenses even though you think it's settled, especially since she's going to start there before your D is over. Make sure it's in the decree exactly how it's supposed to be paid.
