IN recent years, enrollment at sectarian colleges and universities has been expanding rapidly, an expansion fueled in large part by the growing number of women who choose to attend religious schools.  While public colleges expanded at a rate of 4 percent and private colleges at a rate of 17 percent over the last 10 years, the Council for Christian Colleges and Universities, which includes over one hundred Christian liberal arts colleges, saw a jump in enrollment of nearly 42 percent.