Sandy,
The dainese jackets work very well, a bit pricey, but if you're going to be pushing the envelope it's well worth it.

Hubby dh races and originally had an Azonic jacket, broke his ribs on a race in AZ and went with Dainese after that because of pad placement and overall comfort.

Have fun with it, there's a few videos (dirt divas) that show some women freeriding. If you're ever in CO in the summer, there's a freeride/dh event in Silverton that a few pro women seem to attend. It's great seeing what they can do and aspiring to be able to do some of that.

Enjoy!