I am a newbie on here,and I find these boy of the day punishment connundrums rather original and fascinating.
We all get to do the Solomon bit!
Now,with these three little 'terrors', who I can see are just 'all boy',I would probably have to really work at keeping a straight face about their little prank.
I can understand my daughter would be very annoyed, but I would suggest that she does not make herself popular with the boys, dismissing them as little brats, as is the wont of senior siblings.
I also,must 'fess' up to myself,that the idea for their prank, probably took root from my own big mouth.
All the same though,much as I must take some of the blame myself, and much as I may have a little chuckle to myself, the little fellows cannot be allowed to think that misbehaviour, conducted with malice aforethought,will go unpunished.
I will give them a very good talking to,pointing out that they would not like it if somebody played such a joke on them.
I will explain that I cannot allow them to play such a naughty prank and not punish them for it, and make sure that they understand.
Then I would ask them if they feel that they should apologise to their sister?
If they agree that they should, without demure, pouting or sulking, I will go a lot easier on them.
So I will take them to their sister and let them apologise, and hope that she accepts the apology with good grace.
Then I will take them to their room,and tell the boys to take off their pants and underpants.
Over my knee, one by one,the number and firmness of the smacks dependant on their attitude to the apology.
After the spanking, I will tell them that they may not put their pants back on until I allow them to do so,and that if they want to see me, I will be in my office, or the kitchen or wherever I will be.
After some refection time,the kids will normally come looking to say sorry, and want your forgiveness.
I will accept it and hug the little darlings and assure them of my love.
I will then allow them to put their pants back on if they wish.
My kids would sometimes like a botty rub with some baby lotion after a spanking, and this can be a nice bonding time between parent and child.