Sorry to here you're having trouble! Hopefully I can help. What exactly is the nature of the issue? Is the DLC not showing as "Installed" on the game's home screen? Or are you getting some kind of error message?
Viewing post in Our Life: Beginnings & Always - Step 3 DLC comments
Totally forgot to reply (most likely because it was so late lol), BUT I FIGURED IT OUT! I was trying to copy and paste the whole game folder for the DLC, but I really only needed to move over a single file. The instructions were kind of confusing at first, but I scrolled through some of the other comments here and eventually figured it out :)
Anyways, I may or may not have already played the whole dlc, and it was SO worth the thirty minutes of file explorer HELL (Maybe this is a sign I need to put myself in a computer class??)