Legal Question in Family Law in California

There are two ways a court can obtain jurisdiction over assets. It has jurisdiction over assets that are located within its territorial jurisdiction, or it can have jurisdiction over the person who owns the assets and compel the owner of the assets to do or refrain from doing things with the assets. There is no way to tell without all the facts and details of a particular situation whether the Brazilian court would have any jurisdiction over any particular assets in any particular case.

You would have to ask a Brazilian lawyer how the courts of that country would treat assets moved into a trust for the children. In California that would not generally be effective to protect them from allocation in a divorce.