The pics below were my first try taking pics of motocross. Even at car races, I tend to not use the machine gun mode, rather I try to anticipate the movement, get the framing and focusing I want, then I'll take the pic. Sometimes in one pass, I'll take a few shots in succession, but I found either my framing or my focusing suffered on the later shots since I became too focused on other things. My best shots were when I took shots selectively.
I found that SR was probably very helpful w/ these longer focal lengths, but using a tripod might have improved my hit rate. But for panning shots, I think a tripod would probably be more of a hindrance when I want to move around or if I'm on bleachers. I've practiced panning on traffic before and found this very helpful when I did go to a race track. If she takes shots straight on though like the shots below, it's really just anticipation and a little bit of technical knowledge (ie metering the ground and not the sky, using the spot focusing if using AF, choosing the right shutter speed, etc). Thing is, if she's a complete newb though to SLR's, I would lower her expectations as to how many keepers she'll get... pics w/ an SLR can be great, but it's much easier to take bad pics w/ one until one get's familiar w/ the technical side.
Camera: Pentax K10D
Exposure: 0.003 sec (1/400)
Aperture: f/5.6
Focal Length: 180 mm
ISO Speed: 100
Camera: Pentax K10D
Exposure: 0.003 sec (1/400)
Aperture: f/5.6
Focal Length: 180 mm
ISO Speed: 100