My Toddler Who Is Now 22 Months Old Fell And

My toddler who is now 22 months old fell and hit her head on a big sharp rock 4 1/2 months ago. There was some bleeding and a huge goose egg bump appeared on her forehead immediately. The following week we noticed it looked like it left an indentation on her forehead...but you can only see it if she raises her eyebrows or looks certain ways with her face. Will this go away and is there something i can do to help heal it?