Please see below

first, I am sorry about your son's death.  The administration ad prosequendum is for a wrongful death action.  What they are asking you is to give up your right to serve as the Administrator and let some one else take over bringing the wrongful death action on your behalf.  As the child's mother, you have the natural right to be the first choice to be the person to bring that action, but if you want someone else to do it for you, then sign the paperwork.  If you would rather be the one responsible for bringing the wrongful death, then don't sign and contact an attorney yourself.  Good luck.