i don't think the phasing would work. the thing has different settings but it's more...esoteric in some of its effects. hard to prove but i think the energy would effect her even if she tried to phase through it. it can neutralize most forms of energy (sonic even) and of course energy is also immaterial. it can even alter molecular structure i think. pretty sure if he wanted it to, she couldn't defend against it.
Might not work on her, actually:
https://imgur.com/a/able-to-use-roms-guns-which-is-keyed-to-his-energies-yFUv3DM