@CCC:
She made the gauntlets with long-range in mind!
But she doesn't strike me as a gossip (always just holed up in the lab).That's actually a kind of weird element about this whole arc - everyone has all this exposition about the others' Quirks, even though we've seen zero interaction between some.
Maybe we should assume they all observed each other during that one day of forest training, off-panel.
Given her love of showing off her inventions, I could see her going on and on about them and unintentionally giving out information to others.
The fact that class B know everything about Class A's quirks, but Class A doesn't have a clue about class B's quirks unless we as the readers have seen them is a little odd to me, and is more than a little odd in the terms of the story. I get that this is really the Class B introduction arc, but it is serving to make Class A look like they are not doing their homework. The other issue is that Class B seems to have near perfect strategies to deal with A almost like they knew this particular test was coming and prepared ahead of time…