My wife and I are living apart - she says she is waiting for me to die so she can get the whole house. I have (4) sons and want to leave them something. My wife is not their mother but she has (2) sons of her own of which I am not their father. I assume we own the house jointly although I am not sure as it is not listed on the deed. How can I break her right of Survivorship?

Get a divorce

If you own the house with your spouse, you probably own it as JOINT Tenants ( holding title this way gives ROS) can't do anything about it without her signature deeding off title.
Another way though, make SURE she dies before you! Problem then solved.

The first thing you you need to do is get a copy of the deed and review how its worded. If it is ROS, then there is nothing you can do unless she agrees to a buy out.