I agree with BarbaraB and Cheryl that it was a courtesy call,in hopes of not having Mary tag along-also,the Musgrove girls may have wanted someone to be able to explain their possibly long absence from home(for example,if Mrs. Musgrove came by to ask Mary and Anne if they had seen them)...perhaps,one or both of the girls thought they might get an invite to supper at Winthrop(the better to reconcile,my dear!).