Controlling acces to shared document

Controlling acces to shared document

Hi,
I am new in Zoho. It's first online web app for documents that I really like, but I have the problem: I am sharing one Sheet with one person, I've added her e-mail as read only, but the link which this person received is... public. Anyone who gots this link has access to read my Sheet. How to secure my Sheet for password protected access? Or only for Google account login: for me ( I am accessing Zoho from my Google Account and this second person should use her own login information to have access to my Sheet.
Is there posibility for this?

Sorry for english. If you don't understand something i can try write it better - just ask for it please.