Regret
It seems like she's found a lot to be sorry for in the past few days.
She's sorry she didn't trust him to get out of it alive.
She's sorry she didn't try to find him, alive or dead, and left some of the straggling personnel left on the island to notice his homing signal.
She's sorry she wasn't there to help salve his burns and keep him company when it hurt too much to think.
In fact, she thinks ruefully, watching his expression grow stormy and brooding as his eyes light on a newspaper headline about a recent act of heroism by the four people he hates most in the world, the only thing she's not sorry for is the only thing that he really wants her to be.
End Notes: This one because I don't exactly see where Mirage was a bad person for trying to help the Incredibles stop Syndrome, and because I don't generally think that caring about someone has to mean 'believing unquestioningly in everything they do'. And anyway, they've both got a lot to forgive here. ;)