
Females
A typical altered female ferret weighs between 3/4ths of a pound to a hefty 2 1/2 pounds and tend to be more dainty than their male counter parts.
A female ferret is called a jill. (Altered females are called sprites.)
Males
Neutered males can weigh from 2 to 3.5 pounds but an unaltered male can weigh a whopping 4-6 pounds! Now that's a big boy!
A male ferret is called a hob. (Altered males are called gibs.)
picture scanned from Ferrets for Dummies 2nd Edition