When looking over your tickets, you will see something like this.
It shows that your Disney tickets have indeed got Memory Maker included. But when you scroll to the Memory Maker section of your My Disney Experience, it says you don't have Memory Maker!
You don't need to worry. This is just a little quirk in Disney's system due to the fact they don't offer free Memory Maker to anyone but us. It will continue to say you don't have Memory Maker until you first scan your Magic Band entering any park on your first day. The second you scan your Magic Band and enter the park, check back on your app and the Memory Maker will appear as active in your My Disney Experience account waiting for your photos!