I feel this is an average episode, the Terra Nova incident is an interesting plot point, although at moments defies belief (only children survive? They think that Earth did this, seriously? No matter the - apparently very shallow - angst you have, you don't nuke your only far space colony that costed you trillions to set up. Besides, if Earth was planning to send more ships before the stop in communications, why didn't they?).
But anyway, some of the dialogue is nice, like T'Pol explaining that it wouldn't be so good for (each day stupidier) Archer to just take them to Earth and save the day. And the idea of showing the old woman she was the girl in the photo, although obvious, was played out okay.