Final answer:
The information provided does not specify the number of years Judy was an Assistant Choreographer, as it discusses Alaine Alldaffer's casting career instead.
Step-by-step explanation:
The question seems to be inquiring about Judy's tenure as an Assistant Choreographer. However, the information provided does not mention anyone named Judy or an Assistant Choreographer role. Instead, the information provided discusses Alaine Alldaffer, who has a notable career in casting for theatre, tv and film for the past 25 years. She has also held the position of Casting Director at Playwrights Horizons in NYC for over 20 years. Without additional context or information specifically about Judy's career or tenure, we cannot accurately determine the number of years she worked as an Assistant Choreographer.