I don't think you got played? In essence what was agreed upon ended up being exactly the thing that happened? In essence you agreed to pay strangers groceries, guess they had insane charisma to pass that speech check. Does it really matter if they were homeless, destitute or shameless?
Even when I had little money to spend I allways lived by the motto 50 bucks is totally worth finding out who someone is: they screw you over you know not to spend another nickel or thought. I guess if we take everybody into the discussion in an urban setting, that might become ruinous quickly unless you know how to physically shake them, hope you brought your running shoes lol, especially if the first one manages to squeeze out a multiple of that. That people will take a foot if you give them an inch is to be expected, sadly.
Anyway, she went for it and you didn't establish a boundary when you had enough, what might have been smooth to say is: "hey, my fridge isn't as full as that either, let's move on before I get jealous and we split the bag at the exit". Remember, you can just leave. I- I probably shouldn't mention in but I seem to recall some stuff you shared years back, and the cosmetic products might have given me sort of a cosmic giggle in that situation.
Ironically, if you didn't care if she spent it on drugs or gambling or what have you, it would have been way simpler to set a limit. On the brightside I doubt she is undercutting the supermarket shampoo, whom to, other beggars? A sorority of lazy bums? In a way all equally needy aren't they? Might as well stockpile it and not spend money later? #strategic Speaking of which if lack of housing was a requirement you might just have raised an eyebrow at the opportune moment to ask "refrigeration?"... In any case if they try to make a scen,e again, you can just leave, if that's too hard/ being made to hard... you can be passive aggressive: "sigh, I'm neither rich nor do I have time for this game, also you just used up all of my trust" take twenty quid fold them into a ball "whats better? the pidgeon on the roof or the sparrow in the hand?" toss ball of money way, preferably behind or under a shelf, actually run away. I mean it seems you had time to come up with something ^^? I know I'm writing showerarguments again... but to bring it to completion: she followes you instead of going for the money, I would full on go on the offensive: "YOU SPIT ON TWENTY QUIDS? YOU ARE NO BEGGAR STAY YOUR DISTANCE BONNIE!" Come on now you wouldn't make a fool of yourself in public like that, that shit is reserved to me, and I don't enjoy it either. It was probably one of the better outcomes. You still got your banccontact card, right
?!