Sabar ye, mommy, ini very normal fase anak 4 tahun yang attached kat someone! Bukan because kurang perhatian or kasih sayang, but because anak tu explore relationships dan ada favourite orang yang buat dia feel excited (especially if kakak ipar tu layan dia sikit berbeza). Few of my mum friends pun pernah through this, and they said once mereka understand it's not rejection, it gets easier to stay calm. For your emotions, try take 3 deep breaths when dia start meltdown, remind yourself this phase will pass. When she says "I don't love you" (which I know hurts!), that's emotions talking, bukan the truth. A few of us set expectations before kakak ipar datang, "Sis is visiting for 1 hour, then she goes home, and you stay with Mommy", so anak tau what to expect and sometimes lessens the shock. If you're feeling overwhelmed, maybe chat with your doctor or child psychologist sikit, just to ease your own mind and get proper strategies, sebab kadang our stress amplify anak's emotions. You're doing great, really.