Zelda Zanuba Heap, also known as Aunt Zelda, is Sila's aunt and great-aunt to all his children, sister to Theo and Benjamin Heap and lived in the Keeper's Cottage on Draggen Island in the Marram Marshes. Formerly the keeper of the Dragon Boat, she passes her responsibility down to Marwick (Wolf Boy). She died in the company of her brothers, Benjamin Heap the tree and Theo Heap, the Storm Petrel. 
On stormy nights in the Marram Marshes, Zelda keeps a lookout for any Storm Petrels which might be blown away to the marshes and hopes to meet her brother again one day. There was an instance when a Storm Petrel came to sit on Zelda's roof one stormy night and it wasn't not clear whether it was Theo Heap, although he sat on the roof and said she had always had a talent for seeing the truth in the pond to himself.
She played host to Silas, Jenna, Septimus, Nicko, Marcia and Maxie whilst Jenna was being hunted by the Hunter. She taught them how to create Shield Bugs and altered the Hunter's memory so that he believed he was a clown, in order to stop him from pursuing Jenna. She also captured Merrin Meredith who at the time thought himself to be Septimus Heap, and after being shown in the pond that he was not actually Septimus he escaped only to be Consumed by DomDaniel. Later Zelda Revived Merrin, receiving little gratitude. She tried to tell the Sheild Bugs to act as a temporary guardian until once again, Merrin escaped so he could become apprentice to Darke Wizard Simon Heap.
She played host to Wolf Boy and treated him as a son. She spent her days teaching him in the ways of White Magyk and preparing him to be her apprentice so that he may succeed her as the first male Keeper.
Zelda is of medium build, wears a tent-like patchwork dress (which gives her a dumpy appearance), and has a shock of flyaway grey hair, a wrinkled smiling face, and the bright blue eyes of a White Witch.
Zelda is a White Witch and therefore has considerable knowledge of White Magyk as well as Magyk in general. Throughout the books she has also shown a penchance for Potion making by either making them or maintaining them.
It is widely believed that Aunt Zelda has absolutely no sense of taste and cooks dishes mainly consisting of cabbages and eel. The only person (besides Zelda) who can appreciate her cooking is Septimus, who loves her cabbage sandwiches and Petroc Trelawney.
Her house is connected with the palace through the Unstable Potions and Partikular Potions Cupboard that is in both the Queen's Room and Keeper's Cottage. That cupboard also holds the trapdoor that led to the Dragon Boat until the Great Flood, after which it led to the cabbage patch. She's very humble and is an animal lover.
Zelda is sister to Theo Heap and Benjamin Heap. Her brother Benjamin married Jenna Crackle and had six son's. Her nephews are; Alfred Heap, Hengist Heap, Ernold Heap, Edmond Heap, Silas Heap and Garth Heap and she has one neice Lois Heap as well as another neice in-law (Sarah Heap).
She is the Great Aunt of Silas' seven children;Sam Heap, Nicko Heap, Simon Heap, Jo-Jo Heap, Erik Heap, Edd Heap, and Septimus Heap and adoptive grandfather to Jenna Heap. She has a brother in-law is (Titus Willow) and sister in-law (Thomasine Tremaine).
She was aprentice to Betty Crackle, a mentor to Wolf Boy and she also acted as a temporary guardian to Merrin Meredith.
She has a pet cat called Bert which she transformed into a duck (so she could enjoy the Marram Marshes as well as being easier to keep in the Marram Marshes) and also is friends with a marsh creature named Boggart.
She does not always like Marcia as she and her disagree on what constitutes as an acceptable use of Magyk.
|World of Septimus Heap by Angie Sage|
|Septimus Heap novels|
|Magyk · Flyte · Physik · Queste · Syren · Darke · Fyre|
|Septimus Heap · Jenna Heap · Nicko Heap · Marcia Overstrand · Alther Mella · Silas Heap · Sarah Heap · Zelda Heap · Nicko Heap · Simon Heap · Lucy Gringe · DomDaniel · Merrin Meredith · O. Beetle Beetle · Spit Fyre · Alice Nettles · Snorri Snorrelssen · Ephaniah Grebe|
|The Darke Toad · The Magykal Papers|
|TodHunter Moon novels|
|PathFinder · SandRider · StarChaser|
|Alice "TodHunter" Moon · Ferdie Sarn · Oskar Sarn · Princess Driffa · Benhira-Benhara Grula-Grula|
|Colouring Book of Hours series|
|A Colouring Book of Hours: Castle|
|Magyk · The Castle · Wizard Tower · The Port · Marram Marshes · The Badlands|