You're right Grasshopper, I wasn't really clear about that- The trainer is good to experiment and get a feel for the whole thing, but once you're outside, you're outside. You can put the beast into a really low gear and take to the lawn, even on a road bike. Much safer to fall on. But really, you should only fall twice or so- If you keep going down something bigger is up and sombody needs to take a look.
One thing I've noticed, both in myself and talking to other women (and observing them) is that there's a tendency to use a gentle movement on the release. And it usually doesn't work. A lot of pedals want a more forceful push, and a trainer could be a good place to learn just what is needed. A little more muscle behind the twist of the ankle will usually do it, but it's hard to gauge it at first. I rode clipless for years, but when I went to ATACs in a last ditch effort to save my knees, I could NOT get out of them- till I just slammed my foot sideways out of the pedal. They just took a really aggressive push.
So maybe some trainer, some lawn? Repeated biffs to the pavement aren't a good thing. I worry one of us will get injured.

missliz