Even if she was leaving the company, if she is vested she doesnt have to exercise them at time of departure. Options typically have an expiration date that is consistent with all other employees that are long term incentive eligable. The grant dates should be consistent. Considering no one else is exercising option expiration doesnt seem to be the case.

I have people in my company that exercise their options as soon as they vest. It could be just a personal choice/preference so im not looking into it to much.

If all of the long term incentive eligable employees were selling I would be concerned.