Foreign movie not sure might be Korean of father who cheats on wife and mother of his 3 young children so mother leaves him with children and the mistress grows jealous and nasty towards children so she tries getting rid of them by sadly poisoning youngest via food can’t remember what happens to the second child but he got abandoned somewhere the oldest child father takes her to a public/crowded area and leaves her there she runs looking for him and she stumbles in a back yard where she sees her brother with a new family (all I can remember)