
If anyone here read the "Kill the Villainess" the plot is similar actually. It started as the world as part of the book/game written by the author. But as the story progress it was revealed that the world itself is real, it will continue to move forward even after the pre-written story ends. The only difference is in the Kill the Villainess they don't have gods who oversee them so after the story ended their world would eventually collapse. But one character there manage to find a new god. The point is, the characters in their worlds are alive not just something the author create.
Other similar stories is "Not Your Typical Reincarnation Story" & "Reborn as Character that Never Existed"

In the novel, Yvonne is the goddess Leila, but surely there isn't a goddess creepy as that.

Umm... Reading the manhwa... That doesn't seem right... HAHAHAHAHAHHAHAHA. Even in the novel since they didn't really change the antagonist. BUT maybe if they were talking about the OG Yvonne, yes, at least that's feasible... But the thing is, OG Yvonne died very young (I think when she was an infant??). So the demon inside her was there ever since.
BUT DON'T QUOTE ME ON THAT I'm also relying on multiple spoilers lol

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.
This is one of the few stories that really put deep into the FL’s relationship with her family. It's different from other similar stories—where there's a real daughter or heroine—in which the MC just accepts everything, either forgiving their family or moving on and establishing themselves by changing their past behavior to be liked. The story here shows Anna was really hurt same goes for both families.