If you play through the walkthrough carefully, you will have picked up …
… a ball of twine, which can be referred to as either ‘twine’ or ‘ball’. The little brass bell is automatically added to your inventory when you use the command ‘search box’ (or ‘search window-box’).
I agree that the walkthrough is a tiny bit confusing on these two points. I should perhaps have added …
… ‘i’ after ‘search box’ (which will reveal that you’re carrying the bell). And I could as easily have used ‘give twine to girl’ rather than ‘give ball to girl’.
Not sure why I did it that way, but if you’re playing the walkthrough as shown, the problematical commands should work.