Sounds good, sl. These things do take time if they are to be done correctly. And you never know, the "problem child" just might work on changing her ways. I know that when it was brought to my attention that the ways I (occasionally, and unintentionally) interacted with SOME people stressed them out (and I think it was partly their issue in terms of being overly sensitive, but some of it was me), I made a conscious effort to mind my tone of voice, my demeanor, made a conscious effort to ask about how busy they were before asking for something to be done, and it made a big difference in how we all got along.
Either way, you handled it the right way, and it sounds as if the company is handling the followup well. Good job!