California Partition Law Blog
Yes, a third party who has an interest in the property in question may “join” in a family law proceeding. In some specific cases, a third party must “join” the family law proceeding.
California codified a third party’s ability to participate in a family law proceeding to assert their interest in real estate by creating the joinder rules. These rules authorize who is allowed to join a family law proceeding other than the two spouses.