Erin Crocker is not that good. She has a pole in ARCA and a couple of top 10's over there, but in Busch she has gotten her arse handed to her. Her program has been scaled wayyyy back. And if you believe Jeremy Mayfield, the only reason she's still around is she was doing the no pants dance with Ray Evernham .....
Joe is right. When you look at Ashley Force or Leah Pruett the first thing you notice is that they are very attractive, which in turn is going to make them more attractive to sponsors (in theory). BUT, to keep the seat, you are going to have to perform. Case in point, Melanie Troxel Johnson Jr. Very attractive female that has won races. Same can be said for Angelle S3. Another case in point is Erica Enders. Attractive young lady that for whatever reason, has not got the results on the track, so the program is having trouble staying out there racing.
I guess what I have went the long way about saying is the looks thing is both a blessing and a curse. It can open the door more quickly to top flight rides than it would have otherwise, but ultimately you will have to stand on your own merit and prove that you are not just another pretty face because everyone, male or female, races to win.