Tax Fraud on college apps? Am I Cooked?

So in 2023 I earned $1400 from teaching piano and submitted this as untaxed income on my CSS profile a few months back.

Now just realizing that any amount over $400 for being self-employed that I should've paid taxes on it.

Now Northwestern is wanting a Non-Tax Filer Statement and is asking for my 2023 untaxed income. Do I just stay consistent with the $1400 "teaching piano" on this statement or should I curve it a bit and say like some money came from mowing lawns, some from shoveling driveways, and some from music-related gifts? -to avoid the taxes requirements?

Help me :)