Earwig and the Witch

This is possibly the last book Diana Wynne Jones wrote before her death earlier this year. Earwig and the Witch tells the story of 10-year old Earwig, who gets adopted from an orphanage by a very strange couple indeed: they turn out to be a witch and someone called the Mandrake. She misses her friends and is being forced to help out with the witch's potions, but is never allowed to learn. One night, Earwig and the household cat decides to take matters in their own hands and give the witch the extra pair of hands she keeps talking about - but perhaps in a more literal sense than the witch meant... It is a fairly short book for young children, and definitely worth reading, but it somehow feels a bit ... cut off. There are several interesting bits of plot just left lying about, and I can't help wondering if DWJ perhaps meant to write several more books about Earwig. If there are any, waiting to be published I most certainly will rush to read them, because Earwig is a very pleasant acquaintance, and I would love to get to know her better! (Perhaps I will just have to re-read the book!)