hyper-accelerated metabolism that sped up the growth factors of her body, increasing her strength, agility, reflexes, durability and regenerative properties, and causing her bones to grow on command into oversized finger talons or various external shapes such as knuckle guards, blowguns, daggers, spears, and projectile spikes
Marrow's bone-growth powers were first seen in X-Men: Prime. She gained greater control over her powers in Uncanny X-Men (1st series) #346 and X-Men (2nd series) #90. In Spider-Man / Marrow #1, her powers regressed and she assumed the alias "Sarah Rushman". She became beautiful and in control once more in Weapon X: The Draft -- Marrow #1. Although she lost her powers on M-Day, the arms dealer Volga restored a version of her powers prior to X-Force (4th series) #1, in part using an extra-dimensionally derived serum that allowed her to access the genetic "muscle memory" of how her powers previously worked.