Ideally, your wife needs to draft a properly designed will to that testamentary intent.
If your wife doesn't have a will, or the will names you, it will be up to you to dispose of the property (your whole or partial interest in it) as you see if. You may be able to disclaim you inheritance.
It seems like perhaps there is some conflict here betweeen you and your wife and her children from another. Unfortunaely there isn't a form that will make that much easier.
BUT - taking care of this now, in an estate plan, will be much easier.