I’ve only ever seen something like that once. Only in my case, she was an adult, and I ran after her to tell her that I needed to see her consume the host. When I distrubute the Body, I let my head follow them up until I, at the minimum, see the communicant make a motion to consume the host. If I don’t, I follow them.
When I distribute the Precious Blood, however, it’s hard for me to see someone consuming the Body while at the same time distributing the Blood, so I remain focused at that. During my training, I was told to help the EMs distrubuting the Body by watching and making sure people consumed Him, but it’s too many tasks at once.