Stinger is one of the best allies. Why? Well you got 1 atk or thw and a block. It´s unlikelly that you will have 3 allies in play but if you do you can play her anyway with no need to discard one ally. Sure, you need the avenger trait to play it but there are plenty avengers anyway. Furthermore, Avengers Tower or Team-Building Exercise let´s you play it for free. Insane card.

2 cost allies are good. They come down, they do a thing, they die blocking. Great value

Stinger is a one cost ally who doesn't count against your ally limit. Sure, she's a 1-1 but who cares at that cost? 1 of what you need and a chump block is great

She's particularly good for Strength In Numbers or Band Together decks. Since she doesn't count against your limit she becomes an amazing battery to have on the board.

Only downside is the guilt you'll feel when you chump with her when Ant-Man is in your game. C'mon, that's his daughter.