Few things are required to know about your daughter that her age and whether she is an athlete. If she is an active sports person then reconstructive surgery
is indicated as soon as possible with an early rehabilitation protocol
in a Physiotherapy
unit. Otherwise you can manage it by conservative treatment like Physiotherapy for reducing pain and gaining strength of knee stabilizers and muscles around knee joint. swelling will come down with exercises. If it is a recent injury then Physiotherapist will follow PRICE protocol
initially. So you can visit a Physiotherapist who is specialized in Sports medicine
and get examined about her muscle strength and stability capability. Then you can decide to go for conservative treatment or surgical procedure.
wish your daughter a better knee soon..