You can help them by finding some ideas and links for available places.

I don’t recommend you help them financially as you need to look out for yourself.

The trick is to live within one’s means.

When people live in the expensive areas and can’t afford it, that is what you could do: move to a cheaper area, move further away, move out of the city, get a much smaller place, live with roommates, get a second job and so on.

If one cannot buy property, then one cannot buy property. It doesn’t mean sister had to shell her money. He needs to lower his expectations