The theory is cool but please, don't ask us to forgive Peridot. A character doesn't need to be reformed to be interesting. That last episode showed us that Peridot is evil, a fun and hammy kind of evil, and I am perfectly fine with that.

I hate how people try to defend Peridot's actions by saying she doesn't know any better. She's smarter than most people on the planet so she knows exactly what she's doing when she tries to literally murder a child TWICE. She's got no moral compass and gives zero shits about anything other than completing her mission and getting home. "Keeping it together" pretty much proved that since she had no problem experimenting on the dead.