Usually when people having problems that can't be happy at the moment, they attend to fake it, which in my opinion is too wrong, people do it for the sake of their children to not make them feel any pressure, to not bitter their sweet world ect . . But this is wrong (in my opinion) following some perspectives.
Mostly children will understand the faking, children always understand everything, despite most parents attend to think "that's just a child" well the child doesn't have the life experiences that an adult does, or different other things that they might not know, but they are not stupid neither blind & neither emotionless. They see, they feel & they can understand. A child is just like a recorder & they twill remember everything & as they understand they feel how their parents trying to hide something or fight something without their notice, they see how parents care about them in that way but in the same time this might pisses them off, like me, when i was a kid, if i seen my mom tries to make everything seems beautiful when things are messed up, i always used to say "mom don't bother please" also there's so many children that don't understand it as well but the way i enjoy is even pains need to be shared with the children with hope of future, accepting the current situation, with learning to be tough,strong & positive & taking steps to make things good, if they never realize there's hard times, they don't learn to appreciate their happy-good times, & they wouldn't know in today's world you work hard to earn money to buy all the stuff around the house, they never know this value & can't appreciate it, they never become responsible but instead become spoiled.