If you are presently under formal probation and crossed into Mexico to see an ill relative and you did not advise your probation officer of your intent to cross the border beforehand, very likely you have violated the terms of your probation. Whether or not you did is best answered from reading carefully the terms of your probation in the the probation report and resulting order control the terms and conditions of your probation.If you were solely on telephone reporting as the term of your probation and you kept in telephone contact with your probation officer then most likely you will not be arrested for violation of your probation when you re-enter the United States from Mexico.