Yes, if the priority date on your case is current, you can both file the I-485 at the same time, alone with EAD applications.
BUT, this is only if the priority date is current.
You really should have an immigration lawyer help with these important last steps of the process.
PROFESSOR OF IMMIGRATION LAW for over 10 years -- This blog posting is offered for informational purposes only. It does not constitute an attorney-client relationship. Also, keep in mind that this is an INTERNET BLOG. You should not rely on anything you read here to make decisions which impact on your life. Meet with an attorney, via Skype, or in person, to obtain competent personal and professional guidance.