Congrats on your S’s acceptance! Unfortunately Clemson does not offer significant need based aid or merit aid for OOS students like some of its peer schools (some named in tsbna’s post above).
Their CDS shows an average non-need based award (for those with no financial need, regardless of in vs out of state) of $4,287 for Class of 2025. (CDS H2A-O Calc: Calculator - Net Price)
For students with demonstrated need, the average total FA package was around $13K (CDS H2-J).
Have you run Clemson’s NPC? It’s not very detailed, so not sure of its accuracy. I just put in income >99K, ACT 36, top 10% of class and results showed no need based or merit aid, so not quite sure how they award merit aid there. My guess is they offer modest merit to accepted students who they really want and hope to entice to attend with some merit $.