From the descriptions I've read, this sounds like a clone of "Joan of Arcadia" from a decade ago.

Klutzy hero trying to redeem himself/herself -- check

Nerdy scientist sibling -- check

Mysterious supernatural mentor -- check

Comedy and serious life-problems mixed together -- check

Jason Ritter in the cast -- check ( hasn't Jason noticed the resemblances? )

I thought Joan was a masterpiece ruined by network meddling. Will this one live up to JOAN and have better luck?