to understand or to understanding, thanks teachers!

[Help Wanted]

Dear teachers,

I was wondering if I should write:

Miss Sullivan was important to Helen because she had changed Helen’s life from darkness (to understand or to understanding???) that everything had a name until she longed to learn to speak.

Please advise, thanks soooooo much, teachers.

[Casiopea]

Parallel Structure

from darkness (noun) to an understanding (noun)

[Help Wanted]

Thank you sooooo much for advising, teacher Casiopea. ^^