Everyone Loves Baby C

I am really thankful that both Alycia and Sherilyn love Baby C very much and have never once shown any jealousy or resentment towards their little sister. Many times after I had scolded them for being naughty and they got angry with me, they said this to me "I don't love you mummy but I love baby". That shows they really love their baby sister very much. Sometimes, Sherilyn would say this to me when I'm angry with her as she knows that this would melt my heart : "mummy, I love baby", and then she would hug my leg. How can I still be angry with her, right?