Hi
I'm unsure how sure you are that this is an injury. I guess if you saw the actual event...a stumble, caught her foot in some way, something dropped on the toe......then we could be fairly sure it was an injury. The reason I say this is that a swollen toe could also be an infection. Nonetheless, a vet is still needed to treat that.
So let's presume this is an injury and toe injuries are common. The outside toe of the back leg (the pinky) is the most common toe to be injured because the back leg often gets thrown out sideways and collides with soild objects. The injury will be one of three types:
1. A fractured toe.
2. A dislocation.
3. A soft tissue reaction (sprain, etc).
Fractured toes are often only treated with rest and perhaps some bandaging to lend some support and relieve discomfort. Setting the fracture is rarely done. Many broken toes are simply left to heal all on their own. This is often the way with humans too.
We normally replace a dislocated toe "on the spot" when we see the problem if it's reasonably fresh. If the dislocation is old (weeks) often it won't relocate. I see many cases where a dog has lived with a dislocated toe that had never been replaced and it causes no problem.
Soft tissue reactions are usually only treated with anti-inflammatory medications and perhaps some bandaging support.
So, taking all this into account, if this is an injury there is no serious consequences of a delay in having it seen too. Obviously it is better that it's checked just to be sure all is okay and also to ensure it's not an infection problem.
I hope I've been of some help.
Kindest regards, Peter