Ugh, this makes so little sense.
Say what you like about Liz's character arc these days but she's always loved her son. Last time she was face-to-face with Norman he was sinless and she still hated his guts. Why, why would she let him within a thousand-mile radius of Normie? (Also... does she just have custody of Stanley now? What about his grandfather?)
I just can't work out why Peter's reaction in that scene isn't "GET THE **** AWAY FROM MY GODSON" and punching Norman into next month's issue.