In addition to the two hands on the end of their arms, they also have three hands of cards. Another alternative could be handwriting, of which most people have one, but that could be added into the mix.
I’m a six-letter word. If I did not exist, you wouldn’t either. With my first letter omitted I’m an alternative. The last three letters are feminine. The first four letters make an insect.
The missing numbers are 4 and 9. The list is sorted alphabetically by the English spelling of the numbers, so four belongs after five and nine comes after fourteen.