I have a 6 month old puppy that will fetch dummies ,balls until your arm falls of and then finds someone else to throw to her.
Should she be force retrieving trained and is that something a professional trainer to do.
I train all of mine with a force retrieve, but not at 6 months. She is still a baby, let her have fun. Time enough to get serious when she is older.
That said, what are you planning on doing with your pup? Hunting? Obedience? Other performance events? Do you care if she for some reason doesn't retrieve something?
Depending on how serious you and are and what you are doing, it may not matter.
Six months old is WAY too young for force-fetch training. There is no magic age, every dog is different but this is way too young. Force fetching is not pleasant for most dogs and they need some age and maturity to get through it.
You can force fetch yourself but do NOT try this if you aren't 100% committed and have good advice from someone who knows what they are doing. Once you start down the force-fetch road, you absolutely must finish it and do it methodically or you can make a real mess out of a dog.
For now, you can practice the "hold" command with positive reinforcement only and play at retrieving. At 6 mos, every puppy loses interest in thrown toys, don't worry about that.