Hello saba3,
Welcome to the Community. I'll be happy to answer questions so you can continue to navigate the program with ease.
An employee can access your account if they have the login credentials. They can also access your account from a computer/device that has your login information saved. In case your employee was added as a user on the account, you can check this by browsing through this helpful article: Manage users in QuickBooks.
You're welcome to ask other questions as you browse through the article. I'll be a message away in case you have other questions.