So Riri is being manipulated by either her maid or her nanny. I'm guessing she's acting out because she misses her birth mother fiercely, and the person manipulating her is gaslighting her by saying, "It's for you on good", or some such nonsense.
yup miserable life, when getting out of misery (for another one but still) she gotten killed by another random korean fmc taking over lol.
Again it would have been more interesting if it was not a fucking isekai, and the og fmc did dunno use here skill / patience she learned by dealing with her family to win over the little one.