BARBARA BUSH, whose constant civic activity around this city has won her a special local popularity, was out and about on good business again last week--this time on a mission to the D.C. schools. As a participant in the Washington Parent Group Fund --a project that is now winning attention in many other cities--Mrs. Bush presented checks totaling about $10,000 to 14 city schools, with more to come for even more schools. The idea is simple, and the response is growing: it is to provide for certain schools the kind of parent involvement and contributions of enrichment money that more affluent school communities more easily enjoy.

The idea grew out of experiences a few years ago of volunteer attorneys associated with the Washington Lawyers' Committee for Civil Rights Under Law, who were working in the Anacostia region. Eventually, corporate leaders became interested, and the idea spread. Money raised for donations would be matched 2-to-1 by participating schools. Today, there are 16 schools receiving or about to receive about $900 each; if support can be increased, plans are to expand next year to contributions of $2,000 each for 25 schools and, within three years, to help at least 45 schools, and provide "mini-grants" directly to certain enrichment programs developed by individual teachers.

In turn, the local group hopes to win support from the Public Education Fund in Pittsburgh, a new organization that has noted Washington's activity with some interest. Judging from the responses of the schools--and, more important, the students and their parents--that interest is as well placed as the money would be helpful.