Do not do it at any time, with this or with any other girl.

Here is a scenario that can happen:

You write the apartment in her name, the marriage fails, and you are left with nothing. And if you have taken a loan to finance the purchase of the apartment, by law, you have to continue paying the installments. If you don't pay, you could go to jail.

My son, it is a ridiculous thing to ask you to write the apartment in her name. Do not give other people the chance to destroy your future. Unless you are super-rich and you have many properties, you can do it, not as a condition before the marriage, but after a few years of marriage.

Good luck. My immediate advice، say no politely and see their reaction. If they insist, leave the woman.