do u expect a toddler/small kid to to be really strong to hold the Damn chair(with a weight of an adult) and the mom probably damaged her brain/or got an mental illness (idk I'm not a doctor lol)and the father probably blames yujin on his wife's death bro he tried his best to really hold on his mom but what can u do ofcourse his a child he's not that strong yet.
but this is really sad because the mom basically forgot everyone she knows, her son her husband her friend.
maybe after she fell she thought that some kid in something she watched from (maybe a drama or a series of some sort) is her son its probably aaron hunter or some random kid actor (pls yall don't come at me this is just my thoughts about this manhwa :)