Hi Dragon Welcome to the forum.
Yes she does need to show bank statements as part of her financial capability evidence... it is an advantage if u have lots of money ONLY if it's really her money. It's better to show an honest bank statements of what she really earns. An active bank account.
I don't own a house... but I was granted a visit visa. There is a percentage of girls here who didn't have work or any property but still got it.
Just be honest on your application.