Hello everyone! I am a very proud new keeper of two very lovely runner ducks. One of my lovely girls who is much larger than the other keeps getting shaky legs? It isn't all the time only sometimes although she tends to plop down more than the other but other than this she is a super peepy happy duck. She stretches out tall, runs about, eats and drinks quite happily. They are between 4/5 weeks old and I've introduced grower pellets. Are shaky legs something to worry about?