The Fisherman's Daughters

[Anna]

I have an idea in mind for a story--sort of a mix of murder mystery/romance/survival story involving six sisters. The main character is a 12-year-old, Anna (no connection to my username, just sounded right.) The story switches timeframes, existing in two parts--one starting soon before the death of the girls' father, and one in present time. They'll join together near the middle of the story. I'm not sure if it'll be narrated in 1st- or 3rd- person yet--I imagined it as 3rd-person. The father, who adopted all of the girls from orphanages, was killed in a storm while out sailing, the way he made his living. When all six girls are orphaned again, they are forced to make a decision--to hand themselves over to state custody, risking never seeing each other again, or to make a run for it, surviving on what their father taught them. I'm not sure what really happened on the night that their father died, but Anna and her sisters uncover alarming facts about that night throughout the book. I'm pretty sure that the story will end fairly soon after the climax, at which time Aurora, Jesse, Anna, Katie, Naomi and Faith are forced to face up to the truth of their pasts, who they really are, and what their future holds.
Just summarizing what I expect to happen, I think I'll start writing this quite soon...when can I get my hands on a notebook? I need input:
What could I do to improve this plot?
Should I go on with this story? Or is it totally lame?
And are the sister's names okay? I'm fixed on Anna, Katie, Naomi and Faith, but not sure about Aurora and Jesse. (Aurora's 16, Jesse's 14, Anna's 12, Katie's 11, Naomi's 7, Faith's 4.)
I'm pretty sure that a romance exists at some point, although I'm not sure which girl is involved. Most likely Anna, because the narration will be 3rd-person limited.