I have a theory about Bar Lady.
If the speculation is correct that she has a condition that impairs her ability with social interaction and communication (perhaps she's on the autistic spectrum somewhere), then she's probably not had an easy life. Not everyone is as lucky to have parents as loving and supportive as Emily's. If she's been abused and/or neglected, then she's probably quite defensive and this might explain her being so aggressive. It's virtually a survival instinct in a subtly to overtly threatening world.
Having not been supported through education or treatment, her condition has left her stuck pretty much at the bottom of the social and employment ladder, with a low-paying service job provided by a kindly business owner and dependent on what little she can scrape together in tips. I doubt that's much, although something tells me Barry might be as helpful as he can.
It's thoughts like this that make me wonder if she's going to be a new regular character. Slice-of-Life stories tend to always be evolving. As character arcs come to an end, their protagonists start to fade in the background and they become more supporting characters (as we're seeing with Marten and Dora). To keep the story fresh, sometimes you need to add new blood because, too often, giving existing characters new arcs can sometimes seem arbitrary (Jeph was lucky that Faye's new arc with Bubbles is working so well but he might not want to push his luck by taking other existing characters in new directions). So, it's possible that Bar Lady is not only going to be a character foil for Clinton but her journey is going to become a long-term character arc in its own right.
If it can't be solved with a harpoon, it can be solved with a sufficient amount of explosives.
Taken from "The Wit and Wisdom of Lt Gen John J 'Jack' O'Neill, USAF".