If J.K.Rowling was to write another Harry Potter what could it possibly be about; ideas please?

I can't think what she would write about I mean Lord Voldemort is dead. I mean I can't think what it could be. I think that it may lose its suspense etc but if she is an amazing writer so she'll think of something. What do you think she could possibly write about, Draco, Crab other death eaters which survived? I mean if there are any Horcuxes left I am so stumped for ideas of what she can possibly write about! I mean would she start 19 years later? I would like to hear people's theory's