i have the same issue!
Viewing post in Our Life: Beginnings & Always - Cove Wedding Story comments
So I figured it out! you have to download the game so its in your finder and download the DLC then go to your finder, copy the DLC download by using two fingers to clip on your mouse pad, then open the Our life application find where it says game, click to open the drop down and paste the DLC you copied to it and it should work the next time you open the game! - sorry if this is confusing.