Backstory my cousin (24) has been staying with me for two months after a spectacular fall out with my aunt whilst she “gets on her feet”. I agreed to let her stay here rent free whilst she saves up for a deposit on a flat (rented) which should be achievable as she has an above minimum wage jobs and no other expenses aside from phone contract. Cousin has quite a bit of credit card debt (although I don’t know the full extent) which may impact affordability but before she moved in she assured me she would be saving £200 a week which would more than cover a small place (in the north). For full disclosure a few years ago I leant her £3k to buy a car to get to work, she paid me £1.5k back over 12 months and then stop as she “can’t afford it”.
Problem 1: I have quite a stressful job and I like to have a G&T 3/4 evenings a week (too much I know 
) however whenever I have one cousin will ask if she can have one too. At first I said yes of course (as it seems incredibly mean to say no) but it’s now got to the point she’s gone through several bottles of my rather expensive gin (along with me, not by herself I might add), she occasionally says when I point out we’re running low “I’ll buy a bottle” but this has never happened. She has also eaten/drunk all my Diet Coke, coffee, cheese etc when our explicit agreement was that she’d buy her own food/snacks. Whenever I get a takeaway she will add on her order, promising the money which then never materialises. I have brought this up but ultimately I’m not going to sit there munching my Chinese while she looks on in envy.
Problem 2: I am extremely suspicious she is not saving any money and is planning on staying here long term (she has a pretty cushy deal). She’s a terrible spender so I offered to keep some money back for her if she gave it to me - she duly gave me £200 which I ended up giving back after 4 days. I have asked her if she’s saving as she often comes home drunk (clearly having been to the pub) and she assures me she is, but the flat she had secured for two weeks time has now “fallen through” and she’s asked to stay until after new year. I pointed out she owed me £1.5 still and she got very stroppy saying she’d sort it in the new year.
AIBU to tell her she needs to move out in two weeks as we agreed? On the one hand I feel mean as it’s so close to Christmas and perhaps she can’t afford a place of her own. On the other hand she clearly sees me as a soft touch and she’ll never learn unless she stands on her own two feet 