Maewen's mother barely appears in The Crown of Dalemark, and then only by reference. She is said to be tall and willowy. She works as a sculptor, covering strange gawky statues with metal rags and splashes of color, and is very absent-minded.
Instead, Maewen has chiefly been cared for by her mother's sister, Aunt Liss, who feeds her, clothes her, and makes sure she has a horse to ride (Aunt Liss runs a livery stable).
Maewen's mother and father are evidently separated or divorced -- not a good partnership, evidently, especially since both of them seem to be preoccupied with their own interests to the detriment of their child. It's probably just as well that we don't need to put up with Maewen's mother directly in this book, because she doesn't sound like much fun.