OCD responds well to a combination of pharmacotherapy with psychotherapy / counselling. Both have an equally important role to play in achieving best results. It seems that your mother has only been put on medicines. Normally, the right kind of medicines, given in the correct quantity would bring positive results. It might be a good idea for you to seek a second opinion. There are specific techniques that are used and taught in counselling that would help the patient deal with her thoughts and compulsions thereby getting rid of the problem. Cognitive Behavioural therapy works wonderfully well in cases of OCD. I would strongly recommend this for your mother.