Thanks for your message pupsmom61 !
In the meantime I encountered my first hurdle : the G chord. At first I just couldn't do it, the 5th string was always muted, either with the standard or the pinky fingering (I am a real "petite" woman and my glove size is XS). After more than a week of practice it slowly gets better, and I think I am going to be a "pinky G" person : it is easier on my hands that way.
I can do Em-Am-Em flawlessly now, and i am currently working on D-Em-D. Very tough at first but slowly getting there as well. When I have a problem, I search the forum for previous posts about it, and that way I find reassurance that my problem is perfectly normal and that I just have to keep at it as long as it takes.
I love the guitar more and more everyday and I'm eager everyday for the evening to come so that I can practice ! And of course I still find Lisa's course excellent.
The only real failure is the failure to try.