How can I reply to this?
ask her Really! People have misunderstandings all the time, people misspeak all the time. If somebody says something that you don't understand then the proper way to reply is:
Sorry, I don't quite get what you mean by that...
"Sorry" because its polite to apologise, it takes the blame out of the situation.
"quite" means "completely" (in this context)
"get what you mean" is a colloquial way of saying "understand you".
The meaning of the sentence seems to be:
I'd would [prefer] to [teach] you (to do something) (and then you do it, even if you, as a beginner make mistakes at first that I have to) go back and fix. (rather than not educate you and just do the task myself).
Eg. The "task" is "use publishing software to lay out a company magazine. She is an expert. You don't know how to do this. She has two choices. (1) She can lay out the company magazine herself. Or (2) she can teach you how to lay out the company magazine. She knows that you will make beginner's mistakes, and she will have to fix. Later you will be an expert. She prefers (2)