Tomoyo has been acting for over 21 years including over a decade of voice acting, she has more experience than most.
She performed the OP for DokiDoki! PreCure when she was only 16 years old, which you can watch here perform here: https://www.youtube.com/watch?v=v34dNHTGEXs
If you are interested in more seiyuu content, consider visiting the seiyuu subreddit https://www.reddit.com/r/seiyuu/