Thanks for the query.
It appears that the night pains, cramps and coldness is due to a block in the blood vessels that supply blood to her leg.
Massaging may not really help much.
Kindly avoid her walking much now as her leg has compromised blood supply.
She may take Aspirin
, under medical supervision after a meal as this may be of s0me benefit in reducing the vascular pain.
Keep good control of her Diabetes
with proper diet, exercise, regular monitoring and required medication.
She needs to consult Vascular surgeon. A Doppler scan will be necessary to find the block and after that the intervention can be decided. Surgical intervention may be necessary.
Kindly do not delay.
Wishing good health.