@usrhlp I have that EXACT same problem! I go to the marker... no damn cow! Audumbla has already gone!

@usrhlp woah! Scrub that! I fixed it!
Ok so if you have no cow.... your cow has up and left and wont respawn!

Go to the starter pen, smash the fence, push the block in the next pen all the way forward, smash the next fence, and finally smash ALL of the final fence, walk Eivor up through the exit and wait! After standing still for about 3 minutes it should pop up saying Milk of Human Kind complete.

Hope this works for you aswell dude!

@usrhlp I have that EXACT same problem! I go to the marker... no damn cow! Audumbla has already gone!