Edrophonium​ is a drug the blocks cholinesterase from breaking down acetylcholine in the muscles. Why does this improve Annie's muscle function?

Edrophonium is a drug used for the treatment of myasthenia gravis, a long-term neuromuscular disease that leads to varying degrees of skeletal muscle weakness, which results from antibodies that block or destroy nicotinic receptors at the junction between the nerve and muscle. By blocking cholinesterase, an enzyme which demolish acetylcholine, it increases the amount of acetylcholine in the neuromuscular junction improving the muscle weakness

tsd is temerature dependent sex determination.

tsd: it is a type of environmental sex determination in which the temperature experienced during embryonic/ larval development (ambient temperature for development) determine the sex of the offspring.

crocodile displays the tsd where the ambient temperature of the developing egg determines the individual's sex. for example in the american alligator's eggs, incubation at 33 ºc produces mostly males, while incubation at 30 ºc produces mostly females. so if the american alligator's egg will get the ambient temperature (33 degree celcius)during embryonic development from egg, the offspring will be male and same for the female sex determination.