ESR is usually elevated in chronic inflammatory conditions like autoimmune disease
and chronic infections like tuberculosis
As she have stiffness, numbness and pain in fingers and toes, please rule out Rheumatoid arthritis
and auto immune diseases.
Please do the check Antinuclear antibodies and RA factor in addition to CPR as mentioned by your treating physician.
If the levels are elevated, then please consult a rheumatologist
Hope this helps.
Please write back for further queries.
Wishing you good health.