Paying rent to my girlfriend who received an apartment without mortgage as a gift

TLDR: Girlfriend got a very nice flat for $1m from her parents. She wants me to move in and pay her market standard rent and share bills. I don't think its fair as my current flatshare is cheaper and I do not have to worry about bills, repairs etc. (All included in my monthly rent)

My girlfriend never paid rent in her life herself. She was always covered by her wealthy parents despite her working a full time job.

A month ago she received a nice $1m apartment fo free. No mortgage with even the furniture paid by her parents. I'm super happy for her and very excited she is getting what she wanted for a while!

What really rubs me wrong however is that she expects me to pay for half of the flat, market standard rent + bills on top and help manage the flat. While I could afford it, it's putting a significant burden on me finaicially which she is well aware of (its more than 30% of my annual income). I feel its unfair to put myself into a more expensive position plus add the burden of having to manage a flat when I could just stay in my cheaper flatshare and let my current landlord do bills, repairs etc. (Its all included in my current room).

I would be ok with paying 100% of the bills, pay a bit on top and help manage the flat but paying a lot for a place that she doesn't need to pay for plus taking a share of the bills just doesn't stack up to me as I'd pay her effectively a dividend while she keeps her full salary for herself.

It would be great if you could share with me your views on the topic?

It's unfortunately a touchy subject and I'm sacred to piss off her parents who I'm getting along quite well with.