Hi
Keep in mind that Apple Watch cannot be used at all (even for telling the time) without being paired to a compatible model of iPhone.
This is required in order to set up and use all models of Apple Watch, including for managing and syncing with the Apple Watch over time:
Which model to buy is a matter of personal preference.
I suggest that you consider visiting an Apple Retail Store or Apple Authorised Reseller for assistance with viewing, trying on and choosing between available models.
Keep in mind that:
There are two different versions of Apple Watch Series 3. Apple Watch Series 3 (GPS) and Series 1 models do not have a built-in cellular capability. Series 3 (GPS + Cellular) models support a built-in cellular feature, subject to having a compatible service plan from a supported carrier. See below for more information.
Apple Watch Series 3 (GPS) and Series 1 models
Apple Watch Series 3 (GPS) and Series 1 models do not have a built-in cellular capability.
Any calls or data-related services are routed either via the paired iPhone or via a direct connection between the watch and a compatible Wi-Fi network (when the watch cannot connect to the paired iPhone via Bluetooth).
A separate cellular plan for the Apple Watch is not required.
Apple Watch Series 3 (GPS) and Series 1 models can be used in conjunction with an iPhone 5s or newer model of iPhone (running the latest version of iOS) and a service plan for the iPhone from any carrier.
Apple Watch Series 3 (GPS + Cellular)
In respect of data usage, Apple Watch Series 3 (GPS + Cellular) also always first tries to use the Bluetooth connection to your iPhone (which does not require a separate plan for the watch) or, in the absence of that, any available connection to a compatible Wi-Fi network.
If neither of those is available, then Apple Watch Series 3 (GPS + Cellular) has a built-in cellular capability that, under certain circumstances, can enable certain features, which are not available on GPS-only models, to remain available when the watch is used without the iPhone nearby.
The feature involves the built-in eSIM / embedded SIM card in the Apple Watch copying information from the paired iPhone's SIM card, including using the same phone number. The feature requires a carrier plan for your iPhone that specifically includes support for the Apple Watch Series 3 (GPS + Cellular), including the carrier activating the device on the plan:
An activation fee and ongoing monthly cost may apply - contact your preferred carrier for details - not that EE is currently the only UK network to support this feature:
Apple Watch - Carriers - Apple
Apple Watch Series 3 (GPS + Cellular) can also be used without enabling the built-in cellular feature, in which case it functions like a GPS-only model and can be used in conjunction with a service plan for iPhone 6 or newer model of iPhone, running the latest version of iOS, from any carrier, with no need to activate the watch on the plan.
All models
The functions that are available on your Apple Watch when it is away from your iPhone depend on various factors including:
About Bluetooth, Wi-Fi, and cellular on your Apple Watch - Apple Support
Features and requirements that apply under various circumstances are detailed here, including within the footnotes:
How to use your Apple Watch without your iPhone nearby - Apple Support
As previously advised:
More information:
Buy her whichever one you think is appropriate. Keep in mind that she will have to have an iPhone 6 or newer in order to set up and use the watch.
what apple watch should i buy my 13 year old
