Is giving a cat 18th of 1 ativan to much for her?

I'm not sure if it's 1 18 or 18th of 1 ativan

is that to much to give to a cat. I am moving and I'm going on a plane so I want to give the ativan to her.

: http://alcoholdrugstreatment.info/is-giving-a-cat-18th-of-1-ativan-to-much-for-her