Can I press charges on someone who committed fraud and used one of my dependents who we've been raising & caring for since 8/2022 -12/9/2023? Can I press theft charges?

We've been raising our granddaughter since August of 2022 because her psychotic and suicidal mom Elliana Rose Dickey abandoned her when she left her son. Our son passed away December 3rd 2023. The psychotic mom found out and falsified the police report and said we had kidnapped our granddaughter. The police 
gave her to her on December 9th 2023. I believe she's the one who committed fraud because she has been commiting tax, food stamp and Medicaid fraud since 2019. Does anybody have any advice or any help?