The problem with car accidents is that there can be a lot more internal injuries than external. And any anti-inflammatory that you can give her will lead to thinning of the blood, which can make internal bleeding worse.
I would not suggest an anti-inflammatory at this point unless your vet has ruled out internal injuries.
The only way to tell if there is an actual break is to get x-rays.
Keep in mind that losing a toenail is common and pretty painful.
Let me know if you want to discuss this more.
I still would not use tremadol. Some aspirin is the only thing that I can recommend. You can read about dosage info and precautions here:
If she puts NO weight on that foot for more than 24 hours, you need to see the vet with her.