It fails, but you can concentrate on it for a number of rounds equal to your casting ability modifier before needing to recast it.
Elizabeth has 6 ranks and it looks like she can concentrate on it indefinitely. I'm assuming she can't switch targets if one dies, though?
Burn
...If you gain more than 2 ranks in this spell it becomes more useful:
6 ranks: You are no longer limited by the number of rounds you can concentrate on this spell, and it now does 1d8 damage per turn.
Does she need to make a check each turn concentrating on it or just roll damage?
Damage:
Rolled 1d8 : 2, total 2
Spell roll, in case it's needed a second time:
Rolled 1d20+10 : 18 + 10, total 28