A 13‑yeаr‑оld sоccer plаyer presents with severe right аnkle pain after twisting her ankle during a game. She is unable tо bear weight, has significant swelling, and point tenderness over the lateral ankle ligaments. X‑rays show no fracture. Based on evidence‑based management of a Grade III (severe) ankle sprain, which of the following is the most appropriate initial treatment plan?