"that if caught again that they can be charged with something more serious like neglect??"
At the moment you couldn't use the law to prosecute because you would have to show that the level of passive smoking from that one incident did constitute neglect, to a level worth taking it to court.
If the law of neglect was extended then the first prosecutions should come from those giving their children a bad diet, or even sugar, we know for sure how much exposure will cause disease.
I, to, hated my parents smoking, however knowing lots of smokers and having to travel with them, I wonder how many accidents would be caused by people gagging for a fix of nicotine.
I, also know people who have given up and they have been vile whilst doing so, so I can imagine the child having a hard time, especially as they are the cause of the parent not being able to smoke.
I would like no-one to smoke, ever, but I don't think the ban would do what it aims to.