
11 weeks is quite young...and she sound absolutely tinytiny!
But then again,my puppies have been weighing about 9kg at 8 weeks :)...
But as the others say it will be good to start socialising the puppy.
What we did with our puppy was to go to the training field when they had normal obedience training on,we just watched and said hello to nice calm dogs and the trainers...
We felt it is better to socialise her with adults who already know how to behave instead of "brainless", clumsy youngsters!
So at 5 months, when she went for her own puppy classes, she already knew the place and was old enough to have little patience. She had also had some training at home so we could get as much benefit as we could of the classes.
If you planning to keep up with going after the puppy classes I can not see any harm going with her now just to get her well socialised (even if she might be little too young to be able to consentrate for the duration of the class)
You just need to be careful not to let other boisterous puppies to scare or hurt her by accident as some puppies can be very clumsy and not know their own strenght yet.
If you have doggy contacts and are taking her out and about already, maybe you could wait for few more weeks and enroll her for the next puppy classes they have?
I'm sure the people running the classes would understand your reasons for delaying it a little.