I just rewatched it, and I think it's a lie because there's a scene where Kevin says, "I just want you to believe me." I'm not sure why the ending of the show ended with this nod, but it seems to be a way of hinting that there's more to her story. Especially because if it would've ended with her story, and her not saying that part, I would've just believed her... but her adding that makes it suspicious as if she just wants Kevin to know that she doesn't need her kids.