thanks guys... do you think we should begin with machines or with free weights?
Her feelings about machine vs free weights is probably the most important factor at this early stage. If she has emo baggage about barbells like so many people seem to, let her use the machines. Long term, the unrestrained movement of free weights is something to move toward tho imo. Bodyweight exercises are also excellent and lots of gyms have assisting machines that are great for beginners.
Don't forget to assess her flexibility and keep an eye out for joint pain, and try to get her into the habit of taking the time to warmup well. Above all, don't take some House of Pain Animal Pak approach to gym time. Make it fun and something to look forward to.