First of all, remember that an "Interrupt" ability is not a "Forced Interrupt" ability. That being said, it might as well be a Forced Interrupt because a 1/1 ally with 3 health would be one of the worst allies in the game. If you are playing Dust, I think you are relying on ways to buff her attack like Attack Training, Sidearm, and Boot Camp. In multiplayer, or with Cyclops, things like Inspired and Danger Room Training come into play as well. With enough buffs, and in a multiplayer game with lots of minions, she can be a powerhouse. That requires a lot of work, however, so in an average deck you are best using a different ally. I do enjoy though when new cards have a situational yet powerful effect instead of new cards constantly power creeping old cards out of the game.

I think I underrated her early on. Just got done playing her in a storm aggression deck, and with attack training, boot camp and thunderstorm she can clean up the board for 4 damage each, either 2 times and a chump, or a third time. She'd probably loose a lot of value in lower player count, but at 3 players I had plenty of turns she was killing or softening up 3-5 minions, especially with the modulars my son was picking. Even at 3 damage the couple times I couldn't get up to 4, she was well worth the value.

There is a lot of cards like this, but this would be quite good against ultron. You could kill all the drones for one attack. Even if they are more powerful, its not hard to give an ally +1 attack, at least for a turn.