She is considering applying to postsecondary institutions for further education.

postsecondary 由前缀 post-（表示"在...之后"）和 secondary（"中等的、中学的"）组成。postsecondary 字面意思是"中学之后的"，指"中学后教育"，即高等教育阶段，包括大专、本科等院校。