It is quite normal to have pains in the hand at the beginning of a physio career. This can be assisted by looking at the way certain techniques are done and also the just giving the body time to accommodate to the new demands.
Trust me that a physios hands get stronger with time but even then we all get some aches and pains now and then. Espeically if we have a run of clients all sufferinnng from neck complaints.
If she does have an arthritic type issue then neurophysio should be one of the lesser demanding areas on the hands.