"Why do we have Poppy?" --Scarlett
Me, unsuccessfully trying to answer what I consider a complex question, "Um...I don't know! Are you happy we have her?!"
Me, to myself, "Wait, whaaat?! What do I say? I thought this whole "sister" thing was going well...ahhh!" And then to Scarlett, "Do you sometimes wish it was just Mummy and Scarjo still??"
Then I answered her honestly, "Me too! But then I'd miss Poppy, so I'm happy she's here!"
I don't know if I said the right thing; parenting can be tricky! By the time I was answering her for the last time, Scarlett was half listening and had moved on to re-organizing her baby's diapers, so I don't think having Poppy is ruining her life. At least not yet...!