Thank you for posting your query.
Good that you have taken your daughter to a pediatric dentist
and have followed treatment regimen.If your child's tooth has turned dark, the best thing to do is to have your Pediatric dentist look at it. If there are other signs that the tooth is dead such as swelling or an infection that is shown on the x-ray, then your pediatric dentist will probably choose to perform a root canal treatment
or removing the tooth. if clinical or radiographic symptom are not present then your dentist will leave primary teeth for their permanent successors.
It is important to understand that "in the primary dentition of a healthy child, color change alone does not indicate a need for pulp therapy or extraction of the tooth .
Basically, if your daughter's baby tooth has changed color, often the best treatment is no treatment. As long as an infection doesn't develop, simply waiting it out and seeing what happens could mean that your child doesn't have to go through unnecessary dental treatment. And that's a good thing, especially after they've already been through a traumatic tooth injury
hope this helps you