It sounds like this needs to end much like other bad relationships where one person is far more in to than the other. That is you need to be firm and tell her you don’t want any more contact from her.
If you are woolly about the basics then she will continue to ring, pester and otherwise turn up unannounced at your house.
I have friends (well people who hate me the least) who I would do anything for but they are long standing and have been in my life for 15-20 years.
Random acquaintances who got to know me on holiday would be told in no uncertain terms to do one.
You have 12 days annual leave and if she turns up on day 1 I bet she hangs around for the other 11.
Don’t make wishy washy excuses, maybe next time but I’ve got to ride the dog and wash the bike sort of things. Tell her clearly that you do not want her visiting and whilst she’s on tell her you would really rather she f***ked off altogether (feel free to phrase this as you see fit).
Cheers
Danny B