Children’s book stumper!  A child is left at home by parents for a weekend or some length of time, and a neighbor who was supposed to care for her breaks leg and can’t.  Bird (maybe a Robin) hears her crying and somehow shrinks her down and brings her home for he and his bird wife to care for her.  They feed her the flower butter ‘n’ eggs. . . a catbird leaves an egg with their eggs. . . there might be a bird ball. . . she has a marvelous time and eventually goes home. . . I read it in the late 70s or early 80s but I think it was quite old then.  Thank you!