How much evil can you tolerate?

I'm halfway into Philippa Gregory's Wideacre at this point. While I'm enjoying some aspects of the book, I keep getting distracted by asking myself the question above.

The main character, Beatrice, starts off as a young girl in awe of her father and his social position as a Squire. He owns land. She loves the land. That's all good.

There's no hint that Beatrice is actually the antagonist until a short while later when she falls for the gamekeeper's, half-gypsy son, figures out that she's a girl--in the sense that she won't inherit the land she loves, it will go to her older brother who doesn't care about it like she does--and plots with her young lover to kill her father so she can control her brother, who turns out to be in love with her.

As if plotting to kill the father she's adored since early childhood just to keep her hold on land--because her brother will need her to help run it, he's an idiot when it comes to management--isn't bad enough, she has a moment of clarity, attempts to stop her lover from following through, but doesn't get there in time and then tries to kill him to keep everything secret. Beatrice is officially evil. And horribly vain.

I don't mind that the story is told in the antagonist's pov in so much as I have a hard time caring what happens to her. It's more like watching a car accident in slow motion. I'm rooting for her to get caught. She's grasping at straws to stay home and not marry--which she should know by fifteen, is her duty, as much as that sucks. And she's totally avoiding any forward planning past what hole in the damn she needs to plug next. One of these days, she's going to run out of fingers.

Her mother is happy to avoid the truth of what her daughter really is. Her brother is happy to have someone to sleep with who shares his tastes. Her new sister-in-law is happy to be out of her abusive childhood home and is grateful that she has Beatrice to run interference with her 'rough' new husband. Oh and did I mention that sixteen year old Beatrice has managed to get pregnant with her brother?

The whole not even realizing that getting married is bound to happen for a girl, to get shipped off and not inherit, seems kind of like avoiding the obvious for the sake of making the story work. She's also not ever once taken the fact she could get pregant into account with all her jumping to bed, at fifteen, with a commoner who lives in a shack down by the river, which would ruin her reputation to no end and what on earth would mama and papa say? Or what about when she sleeps with her brother? Nope, never once crosses her mind until the revelation that she knew she was pregnant for two months but was hiding it from herself--and us.

Now, onto the story thread that I'm most enjoying: the 'he's not dead yet' young lover. See, Beatrice is evil, but like most evil folks, doesn't check to make sure the person they tried to kill, is actually dead. Evil fail! Now she's terrified he's going to show up, maimed as he is, and tell the truth about who she plotted with him to kill her father. This aspect of the story, the terror of being found out, is done really well, full of heart-pounding, she's-going-to-be-found-out moments. The sad thing is, so far, only one other character is bright enough to suspect she's even hiding anything.

What I've learned so far:
1. Check to make sure your victim is dead! Not doing so only causes convienent plot points.
2. Being an evil character is fine, but being oblivious about common conventions in their own setting/world is not.
3. No amount of excellent description of characters and settting will hide the fact that the other characters are all going far too easy on the MC, easily explaining everything away that should be an anvil.