Marlene has never been able to transcend the source material before, and I doubt she'll do it now.
I hope she gave Sara Shepherd a tropical island for the rights to The Perfectionists. With PLL the first few seasons followed the books somewhat, before veering off towards outright insanity around season 3 or 4. With Perfectionists she just took the names of two characters from the books, Nolan Hotchkiss and Ava Jalal, and scrapped everything else (except for Nolan's murder) right off the bat.
This Ava seems to be modeled after Olivia Jade, which cracks me up, especially since this had to have been filmed before the "Aunt Becky" scandal became common knowledge. And the "security company watching everything" angle interests me. I wonder if that was the original show pitch and they had to graft PLL/Perfectionists onto it to sell it to Freeform.