Their comeback will be: Don't play at 3am! Gotta love parents!
The best encouragement for them that I can think of, is that this is a musical instrument. Parents generally like helping their kids discover new talents. And however far you go with music, it's something that you will always take with you, something you can always do, something that's good for the soul.
Ukulele is an instrument, and when you learn to play an instrument, you learn about music and learn to love music. It develops skill and brings out talent, and is also just plain fun.
The Eleuke specifically helps you practice without disturbing others, or, can be plugged in to disturb everyone! It's electric, so the sound it has is never the sound it has. It can be tweaked and adjusted.
Hope that helps!
/started with clarinet in the 5th grade... it was a bribe to get me to do well on a science project, started with uke in my 30s...