While you can claim them as dependents you can’t claim education credit unless their schools are eligible education institutions.
An eligible educational institution is any college, university, vocational school, or other postsecondary educational institution eligible to participate in a student aid program administered by the U.S. Department of Education. It includes virtually all accredited public, nonprofit, and proprietary (privately owned profit-making) postsecondary institutions.
This information is found in Publication 970, Tax Benefits for Education.