Posted: 22/07/2015 at 07:27
Gardens are full of very toxic plants, potato and rhubarb leaves to name just two. For hundreds of years we've brought branches of berried holly into our homes at Christmas, but the berries are poisonous. Children should not be in a garden (or anywhere else) unsupervised until they can be relied on not to eat stuff without checking with an adult first.
However, if you are too anxious to allow the oleander to remain, I would suggest you look at replacing it with hibiscus http://www.telegraph.co.uk/gardening/howtogrow/3294313/How-to-grow-Hibiscus.html . According to the information I can find online these are toxic to cats and dogs, but not humans.
To remove the oleander just dig it up and take or send it to the council composting place.