They list some Made Easy songs in the course overviews of Fund I and II. I remember those seemed very tough at the time but I tried a few out. They are usually much harder than Lisa's songs but it's good to try and can always come back to them later. I should have used the video speed controls to slow songs down but didn't utilize that until recently.

You'll slowly get better at the songs and you'll be more inclined to stick with them. I really wanted to learn Wild Horses and probably will still play it 20 years from now. Lisa's songs are great as learning tools but I had no desire to perfect them. I had to decide for myself how to balance my time between learning and playing from the song lessons vs. following the curriculum.