Common law wife is leaving a relationship after 20 years. Is she entitled to any land/property not in her name?

Wisconsin doesn't recognize common law marriage.  So, unless the two of you lived in some other state somewhere along the line, where common law marriage is recognized and you satisfied the requirements for that, you aren't married.

So, the woman's rights to property not in her name would have to be established some other way, or not at all.  It is possible, with the right proof, to establish that one person promised to "take care of" the other person for life, and that promise can be enforced in your state's courts.  But it tends to be difficult to prove, and wouldn't give anyone a right to property that wasn't specifically promised.