This may not be the official healthy method, but I wouldn't be too concerned about protecting the pool from your own child. You are virtually guaranteed to already have been exposed to any disease they might have.
That doesn't mean to ignore sanitation, just that there aren't the serious risks of swimming with strangers.
When my young grandchildren swim, I test the pool to make sure the chlorine is where it's supposed to be before they get there, run my pump an extra 3-4 hours to add extra chlorine that evening, and then test in the morning before work. Normal chlorine levels will take care of anything that happens as long as they stay normal and don't drop due to contaminants. One toddler isn't likely to require any extra chlorine, but I do watch a little closer.
If kids outside may family swim, that's when I make an effort to raise the FC before they arrive and then punch it back up after they leave.