Please, DON'T TOUCH

It is often harder to be the guest than being the host. Guests who are very appreciative of the hospitality will not be a problem. That being said, your guests might also be more sensitive than you think. Do remember that even though the child is six, there are parents who still have not gotten over issues being about the child and your belongings and not them and their own sensitivities. I suggest you pack away the most precious and just enjoy your guests and keep your items out that can withstand the odd fingureprint.

If you have pets expect the kid to chase them at full tilt around the room with the usual consequences. Without pets watch for the peanut butter sandwich in the CD drawer routine. It's hilarious!

Simplest solution is a straight-jacket for the kids and if the parents complain, crank up the volume till you can't hear 'em. Truthfully a six year old should understand the word "NO" but in a new envirment anything is possible. Unless your freinds want to hear your system and share your passion I would dis-assemble it and lock it away.

at 6 kids are like magnets for disaster. put your system away in a safe place. even a well behaved child might have an accident.

I would recommend a combination of what has already been said. First, unplug the power from everything. Second, turn the speakers to face against a wall, plugging any ports, and draping cloth over them. Third, disconnect any turntable and hide it on an upper shelf in a closet. Fourth, drape cloth over remaining components. Fifth, tell the parents that your rig is out of service and in a fragile state and you would appreciate it if no one touches it, urging them to communicate this to the child. Good luck.