Hi ! With the history you have described, the nearest diagnosis which one can reach is a cervical spondylitis
. This can further be confirmed by the treating doctor with the help of clinical examinations and x-rays the reports of which are awaited.
If it is cervical spondylitis, it will need some anti inflammatory drugs apart from regular physiotherapy
and possibly a cervical collar
if need be. However, the detailed treatment will be decided by your doctor.
Wishing your mother an early recovery.