Ever had elevated D-Dimer results?

Took my daughter who is 12.5yrs old to the ER for chest pain I figured that they would take the much needed chest x-rays since Dec I have been telling doctors she has chest pain that makes her scream. They ran labs and all came back good with the exception she had elevated d-dimer results. They rushed her into Chest CT to r/o embolisms they said they saw nothing all was good, but were puzzled as to why she had an elevation because that indicates you either just had a embolism burst or one is forming. Still trying to figure out where this is coming from. She is up for MRI’s next brain and chest. Sucks not knowing