If you think about it, this is one of the hardest roles in the show, because the deck is stacked: She should be a bitch, a harridan, a disappointed fucked-up lady. But somehow she is awesome, and not only because Marguerite Moreau is a wonderful angel sent to us from heaven to make things more excellent. She's not an obstruction or a suspenseful red flag or the Doakes, she's a woman. A woman who has made unimaginable changes to her life, and her soul, and has sacrificed a great deal for a man she loves a great deal, with whom she has built a life that as a natural consequence of its architecture holds her up to non-stop scrutiny. There are many ways she could have chosen to make her life easier, and none of them she chose. Plus her kids are adorable as hell.
Down the wooden staircase, half-asleep. Liam's bottle in the fridge, next to the vodka. Fiona finds Ian on the couch in the loving room, all alone. He looks forlorn, but he's also tossing wads of stolen toilet paper at their dad's passed-out drunk face (Turn him over, people! Or actually, never mind. Carry on.) Fiona jokes about the long face: "Just tell me you didn't go and get some girl pregnant" It's a joke but only Ian knows the punchline. He looks down at their dad for awhile, musing. "He hates me." Fiona assures him it's just that he looks the most like their lost mother. "You probably scare him," she says, which brings back his smile. "Yeah, he ain't seen nothing yet." Ian promises he'll find field trip money somehow, hoping she'll stop worrying, but she picks up Frank's legs and shakes out some change, grinning.
"You must get sick of having to think for everybody." The sadness comes back, for a moment, but she tells him the story she tells herself: "Proves I'm wanted." He's amazed by her, the way she thinks this is her life. "Jesus, Fiona. If all you want is to be needed, then congratulations. You've got yourself a job for life with this joker." He's safely up the wooden hill before she starts sobbing.