Gunshot is her main pressure tool for sure, other than that she has F23 and 33 for plus frames but both are extremely slow. She can also do stuff like slightly negative stuff like B2 or 12 into walk back into a whiff punish against pokes but surprise! Superman doesn't really care about that because of F2.
I'm sorry but B2 whiffing is not situational at all, it happens every single time against his F23 for example UNLESS the Superman player is dumb enough to make it at a very long range making both hits whiff, it even whiffs if he whiffs a F23 at a closer range (as I said, he has to whiff it at a very long range, which idk why any Superman would throw out F23 at that point) then she can whiff punish him after he already recovered from the second hit and his hurtbox is not on a flying state anymore.
And point blank it also whiffs. You can test for yourself, try it against a grounded character and then go check it against a flying character.