One of the first steps that should be taken when anyone learns of unlawful use of a Social Security number is to go to the local Social Security Administration office and notify them of the unauthorized use. This generally is done by the "number holder" who must show photo identification and a social security card to prove they are the number holder. They may then be asked to complete and sign a statement that the use is unauthorized.
Since the "number holder" is your minor daughter, it would be appropriate for you to go on her behalf. It would be appropriate to take with you a copy of all information that shows someone (her mother) is using her number and identity.
I hope this helps with the Social Security portion of your question.
I am not licensed to practice law in your state, so any further action that you feel you need to take should involve conferring with an attorney licensed in South Dakota.
Paul W. Hunn