Only you can see the item you bought in your feedback. For privacy, anyone else viewing your feedback can only see the comments.
This won't of course prevent your children from viewing what you bought if you leave your connected device logged in where they can see it.
The best answer may be to open a separate account for buying sensitive items, and make this account feedback private. You can't do this to your main account if you also wish to sell on that account.
All you need to open a second account is a different email address. Both accounts can share the same Paypal account.
