I would not go through my second chance letting the prince grow up happily until he decided to murder me, just kill him while he's a kid or plan to overthrow the royal family sooner rather than later. And doesn't he get sent off to war, but that should be how he meets Erin although it looks like the mother is trying to change that fate
Oh, now that I reread this chapter again. Erin mom called her a birdie, a lark. And Lex/Rowan early on called her his sweet songbird/lovely little birdie/etc. Wow, just, wow.