I would think given her current age and rate of growth, that 60 pounds sounds about right, if by 60 pounds you mean 80 pounds!
Lightning's weight has probabaly tripled since he was 5 months old, but he was a skinnier puppy. Your girl looks solid but not overweight. I'm more worried about her rate of growth. She seems to be growing awfully fast. But I'm not a breeder so someone else will have to chime in on that. What are you feeding her? BTW, she's beautiful.