Karen,
it sounds to me like her pain management plan is not adequate. I would call the doctors on it and ask them point blank if they are following the NCCN oncology practice guideline for pain management. They gave me liquid morphine also, planning on my having a PEG tube but the duragesic was the backbone of my pain management plan. If the morphine causes problems then oxycontin is a suitable substitute. Even though morphine is a relatively fast acting opioid, in tablet or liquid form it could take 1/2 hour for the desired results.

Be sure that when you describe the pain that you use the pain intensity rating scale in table 1, Pain 8-9. of the document in the link I sent you earlier. Also ask her to describe the pain to you - she may not tell the truth to the doctors - we have seen that here before. Older people are terrified of losing their independence.

In the US pain management is a basic patient right.