Thnaks for the advice Frannie - it is similar to an approach we are trying. One website suggested confining the kitten to one room, and letting the two sisters have the rest of the house. In order to "swap scents", the kitten's food is placed very close to the door of the confinement room, and the sisters' food is just outside the same door. They hear and smell each other without stress. This seems to be working - the kitten is much more receptive to the elders now, but it is slow and a work in progress. One sister is very curios and wants to play with the newbie, while the other sis just wants to hiss and growl. But we are getting there - thanks again for the advice!