To be in cahoots means to be working together closely and often secretive or conspiratorial, which is what Momma and Emma were doing to try to fatten the girl up.
Context: "Momma and Emma were working together closely and secretively to try to fatten the girl up."
Hypothesis: Momma and Emma were in cahoots to try to fatten the girl up.
Based on the context, is the hypothesis true, false, or unknown?