Any ideas for spineless, non-poisonus cactus or succulents for a sunny yard? I'm worried about water rationing

I have a small yard with unshaded southern and western areas. I need something safe for kids, dogs, and cats, so are there any non-poisonus, spineless cacti or succulents that don't grow to giant sizes? There will probably be water rationing this year and probably my lawn will die. I'd like something that will still be green at least next to the house. I am trying a thornless prickly pear in one spot (starting with a single pad) and several echeveria (I've heard they don't like intense sun, but trying them anyway) but need other ideas. Thanks!