Something like this?
Incite Effect (Silicakinesis, with Discipline) (At Range) [-2]
Telekinesis (Enhanced, Defensive, Area, Selective, Potent, Self Propelling, Mythic Strength) [-14]
Limitation [+?, I have no idea how to price that but it's probably at least Severe] that your telekinesis only works on silicates and silicon based material (glass, sand, etc.)
Wow. That version is playable in a Submerged game if that's actually a Severe Limitation.
EDIT: Actually, a stunt might be in order.
Razorstorm (Discipline): A bunch of supersonic glass shards isn't fun for people who aren't wearing armor. Against unarmored targets, your Telekinetic attacks using glass deal +2 stress.
Yes, that puts her at Weapon:12 but Shatterbird is noted several times, in setting, to be unwholesomely powerful. Her and the Siberian are the Nine's big guns.