Um, 2 months and 4 weeks would be 3 months old...but anyways....a quick description of a rottie puppy - looks like a baby bear. Ears folded over - not stand up straight - should have a rounder head versus a GSD which has a longer snout - most obvious would be the markings...
You can do a google search for "rottweiler puppy pictures" - it will bring up mostly breeder websites, which is why I did not post anything here...
Also check out
www.akc.org and check out the GSD and rottie breed standards...they have a good description of each breed and what they should look like.
Congrats on the new addition - get her into classes as soon as her KC and worms are all cleared up and the two of you will have a good long lifetime of fun!!!