You could get a Surface 2in1 and install Linux on it, however you will run into issues with drivers as well as app support if your significant other is looking for apps similiar to ios apps.
If that is the case with Windows 10 you can lock down the Surface device to install apps from the Windows store only thereby replicating Windows 10 S mode and enabling tablet mode for a better touch screen experience.
Or alternatively you can get a W10 device with S Mode enabled like the Surface Go 2.
The other alternative is different flavours of Android such as a Fire Tablet or a Android tablet with Playstore etc. Therefore Android and Windows are your only two viable alternatives for now.
Sailfish for instance is far from being mature phone o/s so Jolla needs to alot more work to get it to run on tablets.
Use Sailfish X without any google services and I can run a fair amount of android apps without much issues. However, I wouldn't recommend it to anyone who is not into tweaking settings and fiddling with work arounds on a daily basis.
If you really want a Surface device and want to run linux on it I suggest getting one of ebay for cheap and then testing Linux on it as opposed to a brand new device :winktongue:. You could try a LiveUSB as a taster before rummaging around the firmware.
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