OP, your dog looks fine in terms of weight. She should still be growing, so I, if it were my dog, would be weighing her at Least once a week or two to make sure, but sometimes they just hit a pause. Don't over stress about it, just feed the dog in front of you. Gauge by her activity/energy level, and by her physical appearance. Ribs felt fairly easily are what you want. The entire ribcage being visible, not so much. But yeah, your dog looks to be what I consider a perfect weight.
It's not the size of the dog in the fight, it's the size of the fight in the dog. Mark Twain