About as safe as handing your kids a loaded autmatic pistol with the safety removed
And if you do not believe this then go to your local hospital and ask them about the number of "fell off the mower " kids they have patched up in the last week
When will people start to understand that nmowers are quite dangerous tools, not toys to amuse the kids/ grandkids.
And what do you think it will do to your relationship with your children when the grandkid slip off your lap lands on the deck and has an arme or leg ripped off or turned into dog food by the belts & pulleys ?
"No worries pop, the kid will be fine without a right hand , they do great prostetics now days , were they having fun & giggling before they fell off, tha is all that important"
Now thatwill probably only happen to 1 in a 1,000 but do you want to be that 1 ?