Don't sell your car for half price!
They're adults, let them figure it out, and mommy dearest must learn to tame the monster she created on her own.
These situations very easily turn into repetitive cycles. Next month they'll expect help for rent / utilities, when they're probably spending all their money on non essentials.
Sacrificing half your car's worth is only an emergency solution...
Last time I checked lazy and living above your means wasn't an emergency.
Keep your nose clean, its best