Madonna has enlisted four of her children to help spread a very important message with her millions of fans. David Banda, 16, Mercy James, 15, and nine-year-old twins Stella and Estere united to share a very important "call to action".MORE: Madonna's daughter Lourdes looks identical to famous mum in unearthed school photos"Hi everyone, we would like to thank all of you for your generous donations to Adopt a Bed.