Gailyn Bailey is a child, mutant, and member of the extended "Grey Family" in the Marvel Comics universe.
The character, created by Louise Simonson and Terry Shoemaker, first appeared in X-Factor #35 (December 1988).
Within the context of the stories, Gailyn Bailey is the eldest child of Sara Grey and the niece of Jean Grey.
She and her brother, Joey are abducted and transformed by Nanny into a superhuman duo known as Shatterbox. X-Factor is later able to undo this transformation.
Like her brother, she is a latent mutant and while being hunted by the Sentinels is saved by Roust and X-Man.
She is among the fatalities in the Shi'ar's raid on future Phoenix Force avatars. Before her death, Gailyn and her brother were planning to be adopted by her great-uncle Brian Grey and his wife. Both, along with their natural daughter, perish along with Gailyn and Joey.
Read more about Boobytrap (comics): Joey Bailey, Paul Bailey, Agent Baker, Baldini, Bryson Bale, Balor, Balthakk, Rebecca Banner, Bannermen, Lance Bannon, Baphomet, Barbican, Barnacle, Baron Samedi, Barrage, Omar Barrenos, Batragon, Battering Ram, Battleaxe, Big Hero 6, Bedlam, Beetle, Bela, Bes, Bevatron, Big Zero, Birdy, Bitmap, Black Cloak, Black Jack, Black Knight, Black Light, Black Lotus, Black Musketeers, Black Widow, Blackthorn, Kendall Blaze, Blimp, Blindside, Blindspot, Blockbuster, Bloodhawk, Blue Celestial, Blue Eagle, Blue Streak, Tito Bohusk, Boobytrap, Boost, Bor, Bora, Bouncer, Bounty, Bounty Hunter, Bova, Box, Brain-Child, Moira Brandon, Bres, Melinda Brewer, Brimer, Brimstone Love, Brona, Brother Nature, Abe Brown, Brutacus, Brute, Bulldozer, Bullet Biker, Burke, Jim Burley, Butterball, Byrrah