That's a good point, I don't think my daughter particularly enjoys the application and removal procedure, but it’s only once every two weeks and I think she has decided that the ease of being able to do a quick scan whenever required far outstrips the discomfort, once they are in they are comfortable enough. She is on a pump so used to having cannulas applied every couple of days, but she says the Libre sensors are a lot less pleasant to insert and remove, well they are bigger! It is also worth noting that any CGM system is not as accurate as a finger prick because it isn't reading actual blood and therefore lags behind a little when things are moving fast, so coming out of a hypo is always a good time to do a finger prick because sensors often are still reading low when blood sugar has already returned to normal. Not all systems work for every person either, there have been many people on this website complaining bitterly about Libre sensors falling off or not being very accurate or failing completely after a couple of days use. We personally haven't had any of those problems: sensor accuracy varies but is usually close enough, as long as it’s reading high when she's high and low when she's low and in the middle when she's in the middle then that's good enough for me, it's usually within 1-2 mmol/l of a finger prick, if you are expecting it to be more accurate than that then you will probably be disappointed. (Although I think it has improved over time and there is a software update available which supposedly makes it better, I still haven’t got round to doing that because I find it close enough already!) My daughter knocked one sensor off her arm once, then we had two failures, one died within 12 hours of being inserted and one didn't insert properly so never really got going. Both of those were replaced free of charge. In nearly 4 years of continual use I reckon that's pretty good going. By far the best bit is the arrows and trends, they are far more useful than just the reading alone, if you get a 4.5 at bedtime with a down arrow then you know you need to get the jelly babies out but if you get 4.5 going up then you don't need to worry.
Our experience is only positive and I would always recommend the system, definitely discuss with your niece's parents, see if they can get one on trial to see what they think of it 🙂