A couple of reasons that are not hearsay, I believe:
First, Shirley can help dispell the notion hat KC had the money to pay for a nanny-A nanny who KC told Iasson that she paid a lot of money for. If KC was earning her own keep, why was she not only stealing from CA, AH, LA, JG and RP, but she was also stealing from her grandmother? Whether the defense is going with the Zanny story or not does not matter-KC lied about a nanny kidnapping her child and cannot say who the last person to see Caylee alive was, if it was not herself.
Rick can testify that KC lied about being pregnant. This demonstrates a propensity for KC being able to pass along huge lies when she is feeling fear and guilt....In conjunction with Rick, the state can bring in an expert on filicide, who can testify as to the corrolation between hiding/denying pregnancy and filicide. Even without an expert, the state can make closing/opening arguments that note this and the jury can easily draw the connection in deliberation-What kind of loving mother hides her pregnancy and does not get prenatal care? Was she planning on throwing Caylee in a trash can at birth, had CA not found out? If not, when was she going to tell her family she was having a baby? When she was in labor?
She did not want Caylee, the state may argue that she never did come around to the reality that she was responsible for Caylee....even if CA kept Caylee, KC would still have to have a connection with her daughter-but it does not appear she wanted one, at least not in a healthy and unselfish way.