If the UTH is not on a thermostat, there's a good chance the tank right over that area is reaching close to 120*F, which is why she is avoiding that side. A somewhat 'ghetto' way of regulating the temperature is to raise the tank up about 2 inches so that there's lots of air under the tank, and to get a marble slab from a local hardware store (they're like... $10 usually) and put the slab in the tank on top of the glass that the UTH is under. Doing this, the marble tile will usually be around 85 degrees.