To not go on this holiday

I'd go but stand your ground, don't pay for her if she says she can't afford a meal out say well I guess you will be hungry then see you later. If you've already eaten and she announces it pay your half and walk out. I bet she can find money when she needs to

Tell her you haven't got the money to cover her expenses and keep reminding her of this during every conversation before the trip. If she still comes, you'll have to be strong and ideally put down your half in cash (all too easy for her to ask you to put it on your card so she can pay you back later). If she starts any CFery walk out and leave her to it.

Alternatively you could suggest a pre holiday meal and if she tries to get you to pay for her drinks/meal, just tell her that she is obviously going to expect you to pay for her while you're away so the holiday won't be happening.

I was being serious 😂🤣😂

If you are eating out, take cash each night and eat and drink within that amount.

Having asked the waiter for separate bills, settle yours with the cash.

When she asks you to pay you can say genuinely that you only had that cash on you. It is might be a pain but it instantly stops her abusing you.

I'd take a small locking vanity case to keep items in if you don't want her helping herself.

And non valuable items of clothing if she's likely to help herself.

Earphones and some good books.

Are you all inclusive? If not do some research into restaurants and prices so you have an idea of how much cash you'll need.

You can get travel accounts you top up that let you withdraw money.

It's probably not your idea of a comfortable holiday but sometimes you have to meet the CFkery head on.

Ah.
Here's an alternative idea: You send her a polite but not especially friendly email saying that if she is still planning to come on the holiday, she needs to bring enough money to cover her meals, drinks and outings and enough of her own toiletries to last the trip, because you will not be lending her or paying for anything. And if she can't afford to go on holiday on this basis, she'd better not go. You wish you didn't have to say this to her, but she's freeloaded so often in the past that you're fed up and don't feel inclined to give her any treats.
Then see what she says. She may decide not to go.

Keep toiletries in your locked suitcase.

Agree to always stating as soon as you go somewhere ‘can please bill us separately’.

Also, steel yourself to be as hard as nails financially. Your money that you earned is for you to spend. If you wouldn’t send me £5 or treat me to coffee and cake, don’t treat her either.

Flipping heck, that is taking stinginess to extremes!
What do you like about her? She must be good company in some ways for you to go anywhere with her.

Why not be the CF for a change? Let her pay for everything!

Or, if getting a second room is too expensive, could you send her her half of the money back instead and tell her not to bother coming? Have a relaxing solo trip?

That's great that she agreed last time because it shows she knows at some level that this isn't on. To avoid a repeat performance, make sure you get in first and don't let anything happen that could end up with you paying for anything at all. Meals out will be a danger zone so make sure you say to the waiter before ordering that you need separate bills, and don't agree even to share a bottle of cheap wine with her because it could be the thin end of the wedge. You could turn it into a bit of a game and encourage her to laugh with you - Oho, Amelia, you're doing it again'.

@SoNiceToComeHomeTo's message is perfect. Definitely worth sending it and seeing how she responds.

If she doesn't respond positively, don't make the mistake of falling for the sunk cost fallacy. You have paid for the flight and hotel. That money is gone. Whether you go on the holiday or not, you won't be getting the money back so don't take that into account when deciding whether or not to go.

It's a question of whether the holiday could be enjoyable (either by CF friend sticking to the ground rules or by ignoring her and doing your own thing) or whether it would be awkward and unbearable.

When are you due to go?

You can always vent here.... mn loves a CF thread <rubs hands>

She sounds a right piece of work! But you can do this if you stay focused and head off any opportunity she might take to get you to pay. Ask the waiter for separate bills when they take your order, or only go to self service places where you have your own tray and pay before eating. If she can't pay her own bill, go back to the hotel leaving her to sort it out. If the two of you go out for a drink, go up to the bar and order a drink just for yourself, reminding her that that's what you agreed. If you are firm she'll have to give in and pay for herself or else go off in a huff - win win either way. I have a hunch that once she realises you are serious, she might feel quite embarrassed about being found out.

I wouldn’t go
Youve already paid so whether you go and have a miserable time or write it off and stay at home with no misery, it’s cost you the same

I agree with soNiceToComeHomeTo. Try to clear the air and set firm boundaries before you meet up for this trip. Since you planned a holiday together, you must enjoy her company, so try to claim that back.

Rather than cancel the holiday, you might send her a message acknowledging that things haven't been great between you recently and checking that still wants to come. Then you could say something like : 'It is easy even for old friends to fall out over money, so lets have a clear agreement from the beginning that each of us will pay for ourselves, every time - no buying rounds or treats. We'll eat together if we can find a venue that suits both of us, but otherwise do our thing. Whatever happens, it will be lovely to get away and have a break.' And don't take any extra-special clothes or accessories with you in case she asks to borrow them; take the minimum and say Sorry you need everything you brought with you, so you can't lend anything out.

Is it financial?