HI Lynne, I'm also struggling with that translation. The word 'turn' is because in some countries (at least in Uruguay) we have for example 20 judges in the criminal court and each one has a different 'turn' or shift, and in that way some cases are assigned to the Criminal Judge in 3rd Turn, or 5th Turn, etc. I had to translate that to American English and I was told to translate it as 'Turn' for example, Federal Court --- in 20th Turn. I don't know how to translate 'de familia' because I'm dealing with Criminal issues; but letrado is 'federal' and turno 'Turn'.
(Letrado is also translated as 'learned' but it is old fashioned)