|Full name:||Cecily Lightwood (née Herondale)|
|Age:||15 (as of 1878)|
|Residence:|| London Institute, London|
Ravenscar manor, York (former)
|Family:|| Gabriel Lightwood (husband)|
Christopher Lightwood (son)
Alexander Lightwood (son)
Edmund Herondale † (father)
Linette Owens † (mother)
Ella Herondale † (sister)
Will Herondale † (brother)
Born in 1863, Cecily is the youngest of the three children of Linette and Edmund Herondale. Cecily and her siblings were raised in Wales, believing that Shadowhunters were monsters. When she was nine years old, her older sister, Ella, died of demon poison after the demon Marbas was released from a Pyxis by her brother, Will. For reasons they could not understand then, Will, racked with guilt and fear, ran away from home and went to London to become a Shadowhunter.
Hearing from Will
Cecily and her parents never really forgot about Will, and vice versa. In 1878, it was Cecily's name that Will called out to while he purged himself of vampire blood, leading Tessa to believe that Cecily was someone whom Will was romantically involved with since Will rarely talked about them.
After almost two years of living in peace and isolation in the country manor in Yorkshire, Will found them in 1878 while on a job for the Enclave. Will, along with Jem and Tessa, saw Cecily, in particular, coming home to the manor one morning. Mortmain knew that they would find them and sent an automaton to scare Will, warning the others to stop investigating, else he would hurt his family.
When Charlotte Branwell once again sent Ragnor Fell to investigate the Herondales, just as he did years before, fourteen-year-old Cecily found him lurking outside their home and questioned him. She immediately assumed that he was there to check on them on Will's behalf, and while she was pleased by the fact that Ragnor did not deny it, she insisted that Will should be there himself and return to them if he truly cared. To satisfy her yearning for her brother, Ragnor told her that Will misses her.
Only days after her encounter with Ragnor, Cecily decided to go to London and the Institute there, determined to return home with Will. Arriving at the London Institute, Cecily claimed that she wanted to be trained as a Shadowhunter.
Cecily went on to be trained, also guided by her own brother. It was not as she expected, however, since Will did not take her arrival very well. Aside from her frequent arguments with Will, which usually began when she tries to get him to come back or write to their parents, Cecily also found herself unexpectedly liking the Shadowhunters, whom she believed to be monsters for a long time, as well as enjoying her training, though she did not admit this until several weeks after. Cecily proved to be naturally skilled and attuned to Shadowhunting, much like Will was when he first came to the Institute.
work in progress
She is being trained by Will, and bets him that if she can throw the knife at the target three times in a row, he will write to their parents explaining the curse and the reason why he ran away. Cecily hits the target three times, and orders Will to write the letter; however, he says he will write the letter but that he never promised to send it to them. They end up arguing with each other and Will says he will write a letter to his parents as long as Cecily delivers it and never returns to the London Institute. She refuses to leave and stays at the Institute.
Cecily immediately demands to be a member of the party that travels to the Lightwood family mansion when Gabriel Lightwood arrives asking for help, as his father has turned into a giant worm due to him contracting demon pox. She bravely climbs a tree in search of the giant worm. When Benedict the worm attacks the Shadowhunters, she jumps onto its back, stabbing it with a seraph blade. This act earns her the admiration of Gabriel since she has not had much training. Her time at the Institute awakens her Shadowhunter blood and her love for battle, which leads to her realization that she belongs at the Institute.
When Jem runs out of yin fen, Will promises to buy some from a ifrit den and Cecily follows him, however, he asks her to return home as she is unglamoured in an unsavoury part of London.
Personality and traits
Cecily is a fierce, strong, and brave person, an attitude she developed when she was young. She is extremely loyal, faithful, and caring to those she trusts, as well as very protective.
Typical of the Herondale Shadowhunters leading up to her, Cecily is a natural at fighting. She also has the bitter sense of humor of Herondales, and swears strongly, particularly in Welsh; as a child, she was also said to be quite demanding. Afraid of nothing, Cecily is stubborn and resistant of authority, even if what she is told to do is for her own good. She is also eager to prove herself and often charges into battle if done for those she cares about, willing to do anything, even risk herself, for them and a good cause.
Cecily is also quite a romantic, proven when she tears up while witnessing Gideon proposal to Sophie, and how quickly she found herself falling for his eventual husband, Gabriel.
Cecily is a very beautiful young woman, with gleaming black hair and startling dark blue eyes, traits she shares with her mother and brother. She has pale skin, high cheekbones, and full lips. She is also quite small, contributing to her semblance of defenselessness, and is often assumed to be fragile and delicate, surprising people with her strength because of it.
Bearing a striking resemblance to Will, she has been described as "pretty as Will is handsome." Their similarities have been described as unnerving, as both look almost exactly like each other in their youth, particularly when both look peaceful, and when they scowl.
- Clockwork Angel (first mentioned)
- Clockwork Prince (first appearance)
- Clockwork Princess
- The Midnight Heir (mentioned only)
- Cecily's necklace, given to her by Will, has been passed down the succeeding generations of the Lightwood family. It now belongs to her descendant, Isabelle Lightwood.
- According to a found family tree, Cecily died in 1945, at the age of 81, or 82.
- Cecily and Gabriel are the direct ancestors of the Lightwoods in The Mortal Instruments, namely: Robert, Alec Lightwood, Isabelle, and Max Lightwood.