Each person would have a specific log in but it can be shared amongst family members, but only one device can be logged in at a time using it. We will share one mid- level internet package amongst my family when we sail now that the internet actually works onboard with the new star link system. Theres an option when you log in that says its in use already but you can select to log out other users so you can use it. It became a running joke about booting each other off the Wi-Fi randomly. If anyone needed to do something important on the Wi-Fi we would notify in the group chat in the
DCL app. So if you have 4 people in your cabin you may never need to pay, just share each person's log in within a 24-hour period. The packages also gets cheaper each day, so don't rush to buy it on the first day of sailing. You would most likely have cell signal all day while in port before the ship leaves so you might not need to access the internet anymore that first day.