Since their access to money is limited, and if these people involved are capable of "harming", as Casey insist... you only have 2 choices:
1-Hire a top notch Private Investigator to find Caylee.
2-Bond their daughter out of Jail. (casey is obviously not good at finding her daughter since she looks in all the wrong places all the time.)
If there really are people who took Caylee, they will know if Casey gets out of jail and is getting close to finding her, since the press will follow her/them constantly once she is bonded out. Now, if they use funds to hired a Private Investigator, his work and searches would not be known to the "kidnappers" as easily.
I'd tell my daughter to keep her butt in jail and spend the time learning to knit because our limited funds will be spent finding your daughter. Now if you had not stole from us, we could do both but you have put us in this terrible situation of having to make a choice. Do you want pink or purple knitting needles???