I expected Remote Desktop to be on every system... it's really frustrating that I can't remotely see and configure my elderly mom's iPhone screen when she needs

I expected Remote Desktop to be on every system... it's really frustrating that I can't remotely see and configure my elderly mom's iPhone screen when she needs tech support. "Do you see an x? Or is there something that looks like a backwards arrow? No? A less-than symbol? Or the word Back? No? Cancel? Maybe at the bottom?"