
I heard that the novel is discontinued. How many more chapters before we reach the end?

The novel wasn't discontinued. The author died.
It was up to 500 or 600 chapters when his death happened.
It's unknown (to us) what the plan is for the webtoon. Maybe there was a draft planned for the ending or they plan to leave it at that spot...or maybe make up an ending.
Maybe they don't even know yet and just on waiting until they get to that spot. But it will be several more seasons before that happens.

I love how this story really match to it's title. Most of Manhwas I've seen where the FL reincarnate/transmigrate to the body of the mom. They usually focus on changing her past behaviors and make their husband "ML" like them again. Those stories doesn't include the part on raising children that much. Unlike in this manhwa where the MC is heavily concerned for their children's wellbeing and future. The story also highlights the development of each children.

I think the crown prince death is forced to happen cuz of the original plot of the story that the MC's reincarnated. It's a natural course of event. She only managed to extend his life but probably can't change the flow of the plot. After all she said that they are already near the start of the original story since the MC heroine was about to enter the palace.

Idk for others but I find the villain in this story as unique. In most fantasy story the villains are either dark mage, demon lords, some are even the saint or the religion itself. Meanwhile in this story the villain is a Mad scientist and do experimentations for his desire ratter than aiming of world destruction.

Not gonna lie, they shouldn't stretch the story like this. Fukuchi's death at the airport should have been the end of this arc.
They can bring Fyodor back, but not this quickly—just mere hours after the events, everything suddenly gets worse again.
Why it's a stretch?
Cuz the Decay of Angels schemes started since Cannibalism around Ch.46 and now we are in Ch.121 and it's still not over.
Just because someone is maintaining their beauty doesn't mean they want to eat less (or go on a diet). Their master didn't even order or mention that she wanted to diet, so why did the maids assume she did? What they did was starve her.