That's an excellent take on the scenario. By the look of the spoiler pics, it looks like Ishita is going to use Palak/Payal to instigate differences between Yash-Arti (especially after looking at the pics, I feel Palak's injury is caused because of Ishita but everyone may assume Arti had a hand in this, especially the pic showing Ansh, Payal hands on their mouth, as if they are shocked).
May be when her plan begins to fail she will go to the extreme step of either trying to kill Arti or Yash himself, like the famous dialogue we hear so often - "Jo mera nehin ho sakta voh kisi ka nehin ho sakta"
As said, even after all this.. I don't think PH would dare to show a miscarriage track. As KS clearly mentioned in an SBS/SBB segment, that baccha will take his own sweet time to come 😆