Use betadine, NOT iodine. You can pour a little on the gauze pad and then swipe in along the area in question - daily should be plenty with those small spots. The marks should go away with her next shed.

Question - Does she have any clear scales that seem to be flaking off? It looks like mild scale rot, but is very hard to tell from those pics. If so, then your substrate was probably too wet (different from humidity), or she has been oversoaking in her bowl. Either way, I second Deborah's direction to switch to paper towels until it is gone.