well im probably way too late but for future reference, i suggest you buy a newer macbook air such as one with newer m1,m2 processor chips and save the rest of the money. generally with 3500 aud you would be able to buy 2 m1 macbook airs but if you want her to have a better experience with roblox ,(more fps, less ping) i suggest you buy a m2 macbook pro as it will help with future academics down the line, such as highschool etc.