I would abide by the wishes of the family. If it is private, that will be noted in the announcement. Beyond that, I don't think the decision need have any thing to do with your relationship with her during therapy. Clearly, you've expressed care about her since her illness; that emotion is all the justification needed. I think Snakecharmer's idea of a short note in a card is appropriate and allows you to demonstrate your care. I think I would hold off on the flowers; seems a bit premature funereal to me. And it also puts a bit of pressure on her for a response.