Good to hear that you and the mother were able to talk this out and work together. All too often, at least from what I read, parents and schools go to war with each other rather than working for the benefit of the children.
Haven't seen it yet, but here's an interesting article on the Davis Hammons exhibition at Mnuchin Gallery in Manhattan:
http://www.nytimes.com/2016/03/25/arts/design/david-hammons-is-still-messing-with-what-art-means.html?_r=0
Sorry to read this. I enjoyed his playing with George Russell's groups in the early 60's, and I know he touched a lot of lives with his later teaching career.
Thanks, Mr. Baker.