Yikes on the couch!!
I'm pretty sure that is why that within my home, the sharpies are stored higher and more protected than the knives.

(mostly because at 5 they know to not touch knives, but markers are okay to touch).
As for the clothes, I would lay the stained area over a cup. Rubberband the stained fabric in place over the cup's opening. Then, drip rubbing alcohol over the top of the fabric, so the alcohol drips into the cup. Do this gradually, drip by drip, until the stain is gone.
The ingredient in hairspray and sanitizer that removes ink is the alcohol, so you can cut out the middleman and just do this. If you're inclined, you can also teach your kids some chemistry, since this is a simple titration experiment.