If she'd been left to fend for herself applying for jobs on her own its unlikely she'd have even got a job. Its so hard now to even get a supermarket job as hundreds of applications for one position.
She's been spoiled and has no value of money and just frittering it away as its not been hard won, shes no value of it. Its not like shes spent 6 months applying for 50+ jobs week after week hearing nothing back, doing psychometric tests, tailoring cv after cv and writing long winded answers in online application forms - while working for free in a charity shop to build experience - then one day months later finally getting an interview, preparing for it and then trying her best during the interview - and then getting the job, but its in a shop and they dont offer full time contracts, just part time and maybe 20p above minimum wage - but she'd have been delighted after all her effort and value her first wage after months of no money or a bit of universal credit!
But your partner just gave an 18 year old a £27k job, because why, because she's your daughter? Nepotism at its finest here and your living the consequences.
She has no value of the money or the fact she has a good home offering free board. If she did value money she wouldnt be so careless to spunk £3.5k over the next 12 months.
You've skipped the character building part of life, removed the financial struggle and gave her a good job on a plate.
And youve done someone deserving out of that job, someone who has been sitting at home applying for jobs for months, whether thats their dream entry level job after uni, or an adult parent who's been made redundant and is desperatly applying for anything to pay household bills- of which you read about that on here week after week.
So yeah I think you've literally spoiled your daughter here. Spoiled her experiences of valuing finally getting a job and spoiled her value of money. Its hard to value things if its given to you with no challenge or a bit of suffering.
Not sure how you row back from this mistake and the consequences its now creating in terms of her getting into a financially exploitive situation - she wouldnt be in this situation had she not been just given her job.
Your just living a real life example of "you actions have consequences" unfortunately.
Regardless we all make parenting mistakes and Im wishing you all the best and hoping your dd sees sense somehow.
Idea - Can your partner revoke the job somehow, saying financially its not viable. Or say he can only afford part time like 12hrs per week? Then she can try and get a shop job to learn the value of money.