Another possibility is that your first measurement could have been off. BF% increase without BW going up it sounds strange to me. Also, this client needs to be training at least 2x/week if not more. Is she Type 1 or 2 diabetic? Since she is diabetic, I would suggest training more often will help her with a better blood regulation and better A1C levels. Not seeing her often, gives her the time and excuses not to follow any instructions you might have given her and make it easier for her to lie about her diet, exercise and other habits and changes she is trying accomplish. Have you taken her measurements since then?