It was kinda do or die at this point, so contrary to popular belief, I actually agree with the mom's actions. They've tried being patient, and as is often with cases like this, it only lets them settle deeper and deeper into a rut. There are exceptions, but not Neeko's. The longer you spend with a specific pattern, the harder it is to break out of it.
And notice her face of relief after Neeko leaves the room; she's resolved herself to be hard and stern after a long time of being lax. Heck, imagine having to deal with it for years, family or not; you wouldn't have the same feelings of utter remorse. The type of apology most of the people here are looking for would be counter to her stance, where she's trying to get Neeko back into reality harshly and firmly. None of this means it was actually the right thing to do, but you've gotta shoot where you can, and it caused Neeko's mother no small amount of stress/doubt either, what with knowing how it could go wrong.
Tl;dr, mother did good given the cards given, NEETs might become bigger NEETs, right or wrong action had to be done.