Thanks for all your answers, wasn't expecting for answers this quickly.

@meet.vino : I can't say I'm a big fan of Sailfish OS, even if in this case I could buy a tablet with this OS, but I would rather buy something that is actually on shelf and asap, so waiting for them to get the targeted sum and to produce it, is not an option.

@biketool : was thinking about the Nexus 7 as it thicks all the requirements, but I can't seem to find it new on the market (if you know where I can find one please let me know).... don't need telephony, only data over 2/3/4G

The phone she uses right now is a Nokia Asha (can't remember the model) so I think tethering is not an option. And I would rather have something with build in cellular data.

So, what currently available tablets have the specified requirements.

PS : found a Nexus 7 here, but seems kind of expensive for a 4 year old tablet.... don't get me wrong, if I find something that really worth spending that amount (or even more), maybe I'll do it....