Severe nerve pulling, waddling gait, and

Hello Doctor, My mother (Age 47, Weight 74 kg) has been suffering from severe knee and leg pain for 8 months. Recently, her condition has worsened. She has to stand for long hours at our shop, and at night, she experiences severe nerve pulling/spasms in her legs. Her walking balance has completely changed (she walks with a waddling, penguin-like gait). Her recent blood reports show: Vitamin B12: 221 pg/ml (Low) Homocysteine: 22.30 µmol/L (High) TSH: 7.89 µIU/mL (High) Past Treatment: An Ortho diagnosed mild Knee OA. A Pain specialist prescribed Pregabid CR 75 and Etoshine MR, but no relief. Currently, an MD Physician started her on Tab Thyrox 50 mcg and Tab Becosules Z. My questions: Is her abnormal waddling gait and night-time nerve pulling due to Lumbar Spine nerve compression + B12 Neuropathy, rather than just Knee OA? Should we get an MRI of the LS Spine and Knee joint? Which specialist should we primarily consult now