Hello, I'm Dr. Deb and will do my best to help you today.
Thank goodness that your Aussie's paw wasn't completely run over by the vehicle!
It's unlikely that any bones are broken if she's still walking on the leg and she doesn't excessively react when you feel all around her toes and foot.
I suspect she might be somewhat sore which would be expected and the foot could still swell after a few hours but a broken bone(s) should be fairly obvious soon after the injury.
If she's not currently taking any steroids or nsaid medication and isn't vomiting, then Aspirin may be given which may help with any discomfort/pain she's experiencing or with any inflammation which will develop. The dose would be 10 mgs per pound of body weight twice a day, with food to avoid stomach upset.
Applying a cool compress to the foot for 5-10 minutes several times a day may also be helpful. Be sure to wrap whatever you use in a towel or something similar so that it doesn't come into direct contact with her body.
If you do take her to your vet to be seen, you'll want to mention that you gave her Aspirin (if you do) since it may interfere with what they'd want to prescribe. However, having said that, a dose or two should be fine.
I hope this helps, Deb