In no particular order.
Help, Hard days Night, Lucy in the Sky with Diamonds, Eleanor Rigby, Let it be, Something, Hey Jude, Come Together, Oh Darling, I've just seen a face, Here comes the sun, Revolution, and i guess... if you have too... All you need is love.
ACTUALLY. What you should do is show her the film "Across the Universe". Its a musical chock-full of awesome covers of the Beetles best songs. There are some glaring omissions, but it even has some deep cuts (Being for the benefit of Mr. Kite, While my guitar gently weeps).
THe fact of the matter is, that while the Beetles were remarkable songwriters, they weren't really very good musicians (Blasphemy!). The covers in Across the universe are stylistically varied enough that she's sure to like at least a handful of them.