Stomping the blue alien on the ground will have to go through Bulma first. She's quickly established that Yondu is at least alive and breathing, and doesn't have any injuries that she thinks would be immediately fatal. With that established the little bit of her that was quickly falling toward panic soothes, and instead, she's moving to make sure he's at least in a more comfortable position until they can move him away or to someone with medical expertise. All the while as she's attempting to lug a heavy deadweight much beyond what she's capable of, she becomes more and more aware of closer and closer thudding footsteps.

Vegeta is coming their way, and though it feels as though it's slow, she reminds herself of how tall he is now, and reminds herself that he isn't that far at all. Against all better judgement and ability to preserve herself, Bulma stands directly in the way of stomping Yondu, turning to face her giant, yellow ape of a husband with a defiant set to her shoulders.

... If she hadn't learned to be afraid of him by now, she sure as hell will not here and now. Which is why this small, fragile woman instead points a finger at the giant approaching ape and orders :

"Vegeta! Stop right here!"