I tried to go on my daughters Facebook acct with her permission and although I was able to get in it will not let me log off and go back to my own fb acct on my desk top apple

To get back into your account, log into Facebook and follow the instructions to verify your identity and, if necessary, scan your computer for viruses. If you can't remember your Facebook password you can REQUEST A NEW PASSWORD
You may have the option of confirming your identity by:

• Identifying friends based on their tagged photos
• Answering your security question (if you added one to your account)
• Using your TRUSTED CONTACTS (if you added them to your account)
• Providing your date of birth