I have another thing troubling me.
Marianne wrote:One of the things I find striking about Cosette is her ability to just sort of bounce back and get over things. This, like all character traits, presents itself as a double-edged sword: on the one hand, she doesn't seem particularly traumatized by her childhood; on the other, she was off ogling Théodule though the garden gate while Marius was about to expire of love for her.
That's only my intrerpretation of the character, but I see the ability you talk about as Cosette's self-defence psychical mechanism. Think about her as a small child: no family, probably no steady home, no father, mother abandoning her in the first (most important!) years of the girl's life with unknown people and neither explanation nor preparation (for a reason, but that's what we
know; I do sympathize with Fantine, but let's look at the situation through little Cosette's eyes), abused by Thenardiers, not cared about by anyone, than taken by a strange man and accepting it with no question as she accepted the beatings. Why? Because it has to be like that. Scary and tragic.
She was traumatized by her childhood so much that pushing it out of her mind (never actually possible entirely - subconsciousness remembers, and so does the body, at least according to Alice Miller - which is another annoyingly unexploited motive in the fandom) was the only way for her to survive and not go mad. Learning to accept things that are strange (to us) as normal, learning not to ask questions (like about her mother), possibly not even knowing that she'd have every right to ask them. She accepts herself as Marius' wife as she accepted being Valjean's daughter: he is good, he means good, I am safe and like my surroundings don'taskdon'taskdon'task.
Alas, she accepts Valjean's absence in her adult life as easily. But how old is she then, seventeen? Very young, still. I may not like what she does, but I can pretty much understand her: as experienced as she is in some matters of life (abandonance, abuse...), she is still naive in other (how Valjean feels when she marries - can we really expect her to understand it, keeping in mind that she doesn't know Valjean's life story?).
Her cheerfulness may be another subconscious defence mechanisme: I'm cheerful, I'm happy, cheerful people are liked, you like me too, don't hurt me, don't abandon me, I'm as cheerful and acceptable as I can be. I remember reading (probably at Miller's, I don't remember now) about a child in a concentration camp told by the mother to be cheerful no matter what happens and above all not to ask any questions. The child survived the camp. The trauma revealed much later, in adult life, when the grown up child couldn't cope with abusive relationship, fighting with the only weapon (s)he knew: showing a smiling face and not analyzing anything.
Not that I say Marius would abuse Cosette. But neither of them had what one may call a "normal" childhood. Enough to doubt about the marriage bliss.
As for Théodule, I think Cosette didn't know much what she was doing then and what might it be taken for (as Hugo points out, no matter how much Valjean loved her, there are some things usually taught by mothers and no fathers). And as much as I feel sorry for Marius, could she know how he feels about her and therefore be blamed?
"Believe in the future. Combeferre does."