Considering the given facts and also the images attached, It appears that your mother also has Rheumatoid Arthritis (RA) visible from the nodes in her hand.
Cervical pain if diagnosed correctly (X-ray(mostly), MRI) could be managed easily by taking precautions (avoiding bending of neck, maintaining a good posture) and also strengthening neck extensors and mild traction of neck.
As far as the pain goes , it often comes in the later stages and definitely not alone as pain but initially starting as tingling and then later progressing as weakness and pain. in shoulders, arms then wrist and hand.
relation between cervical and FEET is VERY MUCH COMPLICATED. Which is that feet will only get affected only when CERVICAL NERVES ARE COMPROMISED AND COMPRESSION OCCURS AT SPINAL CORD (leading to Damage at CERVICAL LEVEL OF SPINAL CORD) for that an MRI is suggestive to know the extent and nature of that damage. BUT WHEN THAT COMPRESSION / INJURY OCCURS it leads to weakness prior to pain. make sure you check and compare the strength now and previously. (before the pain started) (ask your mother "agar pairon mein pehle se zyaada kamzori lag rahi hai kya? dard ke alawa".
THE other cause of pain (since you have not mentioned about the nature and exact area of the pain and factors relieving / aggravating) may be because of increased uric acid / arthritis. plus N number of factors depending upon the type and nature of pain and factors influencing the pain
Find out the Nature and Cause. and Fix an urgent appointment with Neurologist (if Cervical is the issue) or a general Physician (if you feel cause and type of pain is OTHER)
DON'T REPEATIDLY ASK QUESTIONS AS THAT MIGHT RESULT IN INAPPROPRIATE RESPONSES, CONSIDER THE MATTER ON PRIORITY BASIS AND CONSULT A NEUROLOGIST/PHYSICIAN AS SOON AS POSSIBLE and ACT ACCORDINGLY. STAY HEALTHY
Hi, please check the ESR levels & C~Reactive protein level and further it can be investigated after this report.Seems like an arthritis .Have to confirm after your blood reports.A comprehensive medical intervention and physiotherapeutic intervention will keep you fit.