so when it is changed into indirect speech, it would be like this :
- She said that she could not help me.
There is a slight ambiguity in this. because. the girl who is talking is referring to another female who expressed her unability to help you.
so, when we change it into indirect speech, as we did in 1, it will mean the speaker was not able to help you, which it is not.
if the other female had a name, like Annie, we can put it like this
She said that Annie could not help me.
hope you get it