If it's just a white rock, it could be a pullet.
It looks to thin to be a cornish cross at that age, legs too thin, stance too thin.
If it really is a sexlink then yep boy.
Meat breeds are designed to grow HUGE in 8 weeks. Table sized. That growth rate works great for meat production. But they grow TOO big for their bone density and their hearts. And most either snap a leg or die of a heart attack kept over six months.
Unless you pen them and calorie restrict...