Go ahead with your plan. Don't tell the parents that you plan to not take the daycare kids. While you have the helper...once in a while take all the daycare kids and see how it goes with an extra set of hands. I wouldn't inform parents of safety concerns as it backs you into a corner later if you try to bring the group. Some parents may call you out on the fact you said it wasn't safe but now you want to do it. Just leave it as something special for your kids who are older and are 'stuck at home sharing mom all week".