The fact that she is ASKING for backrubs is GREAT. Think about it, backrubs can easily become sensual...starting at her feet, moving up, slight grazing of fingers on inner thigh...etc, etc...then telling her to turn over so that you can massage the top of her thighs, etc.
Even when I am NOT in the mood the relaxation and cpnnection established with a LONG backrub can absolutely melt defensive posturing.
I know everyone is different but perhaps "something different" is worth a shot.
