its very dependent on the child. Some can find it induces dizziness and headaches, some are less effected. Bit like sea-sickness/travel-sickness or other motion/vision sicknesses.
Generally it also depends on your budget. There is quite a wide range of devices from very cheap to very high quality and pricey, and you really don't want to be going that cheap because those are the ones that really cause issues.
As for can she play? How tech savey is she already? Modern VR systems (like meta's) are not really any more complicated than a tablet or phone once they are set up. Similar system of home pages, app stores, apps, game interfaces etc. So if she can do all that on an Ipad, she will likely be fine. But if she has never been independent on a device before, it will likely be hard.
Is there anywhere near you that she can go to try it for a bit? I'm not in the U.K. but where I live there are arcades/amusement places that have VR systems that you can pay to go on/experience... that would be a good test to see if she likes it, if she can use it, and if she feels sick etc.
If she is ok, then they are pretty amazing systems these days. Just the 3d drawing apps alone would have amazed me as a kid. Being able to see the room I'm in, and then draw in 3 dimensions and move around to see the drawing from all sides would have blown me a way at that age. let alone the actual games.