I let kids hold mine all the time, but I use a strict procedure to ensure against mishaps.
Giving:
1. When handing your blaster to someone, offer them the grip while holding the T-tracks.
2. Show them where to put their other hand (under the stock/ around the tracks).
3. DO NOT LET GO UNTIL THEY ARE HOLDING PROPERLY WITH BOTH HANDS.
Receiving:
1. Grasp firmly around the T-tracks immediately, don't snatch it, but don't be hesitant.
2. If you grasp from above, they won't let go as quick because they aren't sure if you're holding it yet.
BTW kids love it when you show them how to hold it properly, it adds to the experience.
Always give them a
"Yeah, that's the way you do it!" or
"You're a natural, have you ever thought about joining the Empire?"
once they have a proper grip.