Hi there,
Quite early on I would do hair cutting terms so that this lady can communicate with English speaking customers about how they want their hair done - long, short, layered, permed, dyed, and then get her to look through all the gossip magazines in her hair dresser's picking out different styles and describing them in English.
She'll find that more motivating than the alphabet. I wouldn't teach the alphabet at first myself, seeing as it's not something that we use in conversation, like EVER! It would be more useful to do phonemes for pronunciation.
All the best
Shelley
One to One tutoring for KIDS Teen/adult classroom games