Yes, Jackie is a bird.
But Marshall is soft...and passive-aggressive. She told him to "boss up" and instead of checking that bytch and letting her know THIS IS WHO I AM he took off running. Regardless of where the intention sprang from. she wasn't wrong about him.
What you see with her, Marshall and Josh is the power of polarity. She's attracted to Josh beceause she has a masculine disposition and he's just like her. When you're young/immature you seek out sameness in people, to feel secure and like you belong. When you're older and get bored of going in circles with your self, you seek someone who can help balance you out, not reinforce everything you already know about yourself.
She needs a man with Marshall's more feminine dispositon...fire needs water to thrive. You can be laid back, quiet, even emotional but you can't be WEAK. There are dudes like Marshall that could have stood up to her without running away.