How can I prevent a family organizer from receiving emails about purchases?

I recently made a subscription purchase for which I’d rather keep private from my family organizer. Before doing so, I disabled purchase sharing and transferred the appropriate amount of funds to my Apple account balance. The purchase was made, $19.99 was deducted from my balance as expected, but the family organizer was still emailed a purchase receipt.

This is a completely unexpected result for making a purchase with my own money on an account I have full control over. I’m an adult, and my financial activity shouldn’t be made public to anyone—especially when there’s no disclaimer about sharing it.

If there’s a way to avoid this in the future, I’d like to know. Otherwise, I’m at a crossroads in continuing with the purchase and use of Apple products.