Trapped Nerve after Sprianed Ankle...?

Sorry this is a long post but I need to tell you the full background to this in the hope that someone out there can help
My 12 year old daughter sprained her ankle 10 weeks ago. Since them the ankle has become less mobile that it was at the outset and her pain has increased.
Further to this her ankle has now turned out at a 45 degree angle and has become increasing stiff and immobile
Regular physiotherapy over the past seven weeks has not helped and the physios have now placed her on antidepressants and referred her back to the Consultant as they fell that the problem is Psychological.Yesterday she was subjected to two physios accusing her of making this up and asking questions about her home and schoolife to look for a reason for her behaviour (their words, not mine)
Her symptoms include acute pain in the area just above her ankle bone, numbness to parts of the ankle, frequent discolouration to her toes, sharp shooting or stabbing pains at about 10 second intervals and her muscles in the whole ankle and joint are extremely tense to the point at which she cannot relax her foot, even when asleep.
She was placed in a cast for a period of one week about a month ago but whilst this improved the position, as soon as the cast was removed the original misalignment returned.
She is now awaiting an MRI scan but that is still weeks away so I though of trying alternative therapies.
I borrowed a TENS machine from a friend with the hope that that would dull the pain to a point at which she felt comfortable in moving the ankle.
I placed the electrodes on her ankle and turned on the machine but even at its highest setting she had no sensation of the pulses being sent to her.
Having removed the pads, I tried the machine on the other ankle where she could feel the pulses immediately.
I them began trying the machine at different intervals down her lower leg starting at her knee which was fully sensitive to this form of therapy. However as I moved further down her leg the intensity had to be increased to gain the same effect and when I reach the area just above her ankle bone (form which most of the pain derives) she was unable to feel any of the pulses with the machine turned up fully
I was wondering if anyone can shed a light on where we should go from here and what the problem might be
Could it possibly be a trapped nerve ....?
A friend recently had a nerve block which resulted in similar symptoms and caused her ankle to turn inwards which makes me wonder if the problem may be related to some sort of nerve damage.

[grantlfc81]

How did this pan out for your little girl? i have very bad ankle pains and are long term. im 28 now and had them for over 18 months.