if she experiences no pain, and can reach O, then you must figure out what is holding her back. She probably is not aware of it herself.
Could be a combination of things, poor self image, guilt, etc., etc.
Is it possible to get your bedroom pitch black so you can't see anything? This might overcome the low self image. Guilt can sometimes be overcome with a blindfold and restraints.
Convince her and yourself that you have become an ass-man, rub oil all over her ass and slowly include direct and indirect clitoral stimulation. The whole time talking about how much you like her sexy ass. Use both hands in various positions, sometimes holding lips wide apart for better access to the clit, and sometimes one hand hitting the g-spot while other hand is attending to the clit, or light spanking.
