It appears that Hilda and Blossom are not the only people who have been storing gear in the basement.
It seems strange that Gabriella is being defensive about being prepared for certain… activities. She and Fedya have been quite shameless about their relationship so far. You’d think Gabriella would be quite honest about how she’s set a storage room aside for… personal use.  That way, she can tell people to stay out of it.
On the same note, it occurs to me that for assorted reasons, Hilda and Blossom are probably much better at hiding things than we would assume they are. (Though, on that note, I am not completely sure. Just how “talented” the two are in these identities.)