The first such peril relates to her insistence on freezing April in place as a high school student. We happen to know that if Lynn had her druthers, the youngest would be Aypo forever and we also happen to know that Lynn's fragility in relating to her children seemed to have reached its peak when they were in their teens. Factor in her self-satisfied ignorance of what goes on in today's world and need to look at children through the eyes of a reproving old lady filled with fear and hate and you'll realize that a potential reader might be attracted by how completely off the wall her look at what she thinks day to day life is like. It would be as if she were to try to pass off a Road Runner cartoon as a documentary about wildlife in the US Southwest.
The second and third perils are, so to speak, brother and sister and relate directly to her blinkered vision of what constitutes proper behaviour. First off, we'd have April's insane jealousy of Becky go pretty much unopposed by anything like reason, decency, integrity or anything bad that limits Lynn's need to meet anything like disagreement with maximum force. The sitting duck antagonist would be accused of any number of crazy evil things while such accusations would have no more solidity than Liz's claims that she wasn't a spoiled brat who slipped and fell on her arse because being told to behave with something approaching decorum made her too angry to look where she was going but the victim of evil career woman French person mind powers.
Now that we've made of Becky someone who's totally a monster because April's totally not jealous or insecure despite both such traits being betrayed by her choice of language, let's point out the third, crucial peril: sanctifying John and Elly's emotional and physical absence from the plot. I remember that in one of her retcons, Elly dismissed the attention Becky's parents were paying her as the same sort of family politics that inspire Mira to somehow intrude on Mike's life instead of letting the Pattersons' sacrifices pay off. This tells me that it's going to be seen as being good and noble of Elly to be a distant and disapproving presence that is as afraid of participating in her daughter's life as Lynn is of being an actual grandmother. At some point, Lynn would be made sad and angry when it's asked where John and Elly are when April needs them when it's clear to her that doing so would mean that they'd lose family politics and be their child's servants.