Ridding Belladonna Risk to Babies

Could you tell me how to get rid of belladonna? I have it growing in my yard and I have two babies and I don't want the risk of them getting it. I pull it out and more comes back. It is covering my back fence. Please let me know if you have any ideas.

You say that your plants are covering your back fence. This does not suggest to me that you have the true belladonna, known botanically as Atropa belladonna. Belladonna grows more like a bush reaching perhaps 60 cm (2 feet) high. If your plants are more like climbers or sprawlers ascending up anything that provides support such as tree or fence, then you may have a plant that is entirely different from belladonna.
Bittersweet, Solanum dulcamara, is a shrubby climber that is apt to cover fences as you have described for your plants. Like belladonna, it is a member of the nightshade family which includes tomatoes and potatoes.
So the first step is to make sure of the identity of the plants you have.
Belladonna should be easy to remove. Pulling plants should be enough to rid the area of them. On the other hand bittersweet is likely to regrow from the roots and requires repeated cutting down to the soil, plus digging down to the roots, over a period of several months to rid the area of bittersweet.