Actually she can't, since she can not represent him in court.

And unless she is a doctor, she can not prove it anyway.

Next it is more than just the meds, you will have to prove at the time of the crime, he did not know the difference between right and wrong, That is often the real issue, even if the meds were effecting him, if he knew the difference he is still responsible.

you will need medical experts to testify in court at the trial over this