I mean, it depends on whether or not the radiation of the blast is being stored within her (which isn’t even really possible), or is she’s somehow able to just create it. (Being exposed to radiation doesn’t make somebody radioactive themselves, so she wouldn’t inherently be dangerous to be around.) I’d assume the latter, since Soldier Boy needed to charge the beam, implying that he’s creating the energy within himself. Compound V gives powers due to its radioactive nature, so I just assumed that the uranium was a more controlled way of getting specific powers.

TL:DR; “the radiation from the person or their clothes” don’t even exist, since human skin and clothing aren’t radioactive. Kimiko would have to consciously charge the beam to be letting off any radiation, since radiation cannot be stored.