Just don't lose your cool and be patient. I did freak out when I first tried to tame it bc the mother would aggro on me all the time or just get too far away and it wouldn't work. So I killed any other dinos around that could be a threat to the mom, got more eggs, (Rex eggs, the best ones I have at the moment), and used an Argentavis to drop the eggs not too far away, just enough where I would be able to see the big bird. Used full ghillie suit. The mother eventually gets back to the nest even if she hasn't eaten all the eggs, then you have to get away, and wait for her to go back to eggs, and that's how it goes. The taming effectiveness won't go down if you get out of the nest, only if you get the minigame wrong. In my singleplayer that on 4x for taming, just 4 eggs were needed. It's a super fun tame once you get it right, and it's absolutely worth it. The babies are the cutest ever