Rather than keeping her conscious like that, why not submerge her into persistent vegetative state? That way, it consume less resource because we don't have to pay cook to prepare meal when transfusion of sugar water and other necessary nutrient would do, no episode so no furnishing is damage (as far as I gather, it only happens when the subject is conscious during an episode). Hell, this way it don't need furnishing.
Well, there's a lot of SCPs that cause decay to things around it, most prominent are 073 or 804. There's some potential in this entry, but you'll really have to work hard to make this thing unique.
EDIT: removed the In Character tag.