Janel, I second the triptych. Not traditional, but it will get attention and win some awards, in all likelyhood. Lexie's a great model. Paint her horizontally in the order you've posted.
Check out some of Scott Bartner's very sincere portrait series, as an idea.
Seriously, even if you only use #1 as a reference, you are in great shape! I do sense the echo of Vermeer, if that's what you are suggesting.
Garth