On 97b, It seems strange that Shmuel says that a ktana can not earn (more than five slaim), which is why we are not choshesh that he told her "tzi mai'seh yada'yich l'mezonosayich". But on 97a, a case of a ktana who indeed earns more is a nafkah mina between the two possible reasons of Shmuel? ( Unless the Gemarah itself is saying the nafkah minah may be outside of the ordinary case, but if it does happen, that would be a nafkah mina?!)
Yonatan M., Toronto, Canada
I agree with your answer. On 97b we say that we do not suspect that she agreed to keep her work money instead of food support, as a minor doesn't usually earn that much. However, it would clearly be possible, and that is the Nafka Mina, as you pointed out.
All the best,
Yaakov Montrose