Unscholastic

Both characteristics were so well developed that the hours they spent in the schoolroom were chiefly devoted to exploits of a most unscholastic nature.

You are not free, yet, to be as useful at home as you would like to be; your mother has to do without a daughter, to a large extent, or to avail herself of one with the uncomfortable feeling that the daughter is losing valuable time thereby, and probably is considering herself a martyr in having to do unscholastic duties.