Hi mary klein,
Please login with your adobe id on this link:
Click on the check box of personalized link option.
It will be restricted to the person you want to send the document.
Please note that the personalized link is NOT restricted to the recipient. It is a unique link that allows you to see whether or not it was used, and the link is sent only to the recipient you specify. If you specify multiple recipients, each one will get a unique URL.
But the link doesn't require the recipient to sign in or otherwise 'prove' who s/he is, so if the recipient forwards the link or posts it publicly, others would be able to use it to access the file(s) you sent.
Thanks, this info is helpful.