That's really have to depend tho. Both of you do not need to worry about not having your own flat after marry. But of course, not having a flat does not mean you cannot get marry, maybe just rent a house first or stay with your parent instead. It is always the best to have a house of your own at the end of the day
i think she just feels insecure ba. Probably just want you to be committed or at least show her that you're committed to starting a family with her - not saying she wanted kids, a family can consist of the couple only