The verb Andar has several meanings. Among them
Ir de un lugar a otro (dando pasos).
Which basically is "to walk" or to "go from one place to another". It can also mean
estar (hallarse en un determinado estado)
With the connotation of "being in a particular state, condition or mood".
It can mean so many things that, given the short sentence, the lack of context and that we don't know where your teacher learn her Spanish is impossible to know for sure. The sentence
Anda la juez is not a colloquialism or expression.
One guess is that it could be using the meaning of the entry #8 of the link
with the meaning "the Judge made a decision".
Ande la juez would then be "May the judge make a decision" and
Anda la juez would mean "The judge is making a decision/ the judge makes a decision". But this is just a wild guess of mine.
Again, there could be other meanings shall the sentence not be that short.
Anda la juez preocupada The judge is worried
Anda la juez encorvada/lentamente The judge walks hunched/slowly