I have gone through your query regarding pain in throat of your mother, as you said that your mother had consulted two doctors and prescribed medicine Amoxicillin
is not helping.
Considering all aspect of your complain I think till now it is not clear weather she has problem in her tonsils, base of tongue, palate
, walls of pharynx etc. I would like to advice you to please consult an E.N.T.specialist he will after doing thorough clinical examination may reach to correct diagnosis than after treatment will be possible.