Hi Littler Song,
It is definitely not too late for you to teach your 2-year-old; some parents even started later than you did, and their kids still learned a lot!

About the Alphabet song, it is already included as one of the default Categories in Little Reader, which you can also see when you do a free trial. You can find it by going to LR's Playback Screen and selecting Categories. Towards the end of the Category list you will find both "The Alphabet" (has only the letters) and "The Alphabet Song" (the actual alphabet song, "..now I know my ABCs...")
I hope this helps!
Cheers,
Kezia