Captain Keller asked the director of Perkins Institute for the Blind in Boston for help to teach Helen.
Is the sentence correct? If not, how can I rewrite? Thanks a lot.

I asked her for help to teach my sister.
Correct the sentence. Thanks a lot.

Dear grammarians,
Please help me with the above question.
Thanks in advance.

Both sound a tad awkward to my ear. Suggest changing "to teach" to "in teaching."