My cow wont share

Milking Sadie has been pretty uneventful, however she has decided, I think, that I am no longer important enough to get milk.  Even though I do give her this nice big bucket of cubes.  Yesterday we got 3/4 of a gallon.  Today we got just over 1/2 of a gallon.  I'm not sure what is going on.  Monday I got 1.4 gallons.  I will need to look into that.