vom keisser wappen has a pretty good growth chart.
Vom Keiser Wappen - German Rottweiler Puppy And Dog Growth Chart
I always worried my first rottie was not growing like he should. I got him when he was 6 weeks old and weighed like 5 lbs. It seems like all the sudden he hit a growth spurt and grew like a weed. When he was 10 months old he weighed 120lbs and was like a train coming at you. I would run him about 3 miles every other day 10 minutes after he ate then half a cup of food after the run to replinish lost nutrients and to repair muscles broken down from the run. He was a great dog. Like bruno's mom said make sure she is free of worms. My 6 wk rottie had them which was slowing growth. Worms take all the nutrients from the food the dog needs.