Can i use a third generation iPad to stream Netflix Britbox and Amazon prime

In one word, no.

In detail...

Presumably you are in the UK.

In the UK, Britbox is accessed using the ITVX App - which requires iPadOS 14 or later. Netflix requires iPadOS 17 or later, while the Amazon Prime Video App requires iPadOS 15 or later. As such, to stream all three of these services, your iPad must have either iPadOS 17.x or 18.x installed.

A third generation iPad (a.k.a. IPad3) cannot be updated beyond iOS 9.3.5 (WiFi Only) or iOS 9.3.6 (WiFi+Cellular). With benefit of this knowledge, you can see that the iPad3 does not support the Apps required to access the named streaming services.

For information, here is a list of the highest version of iOS supported by the older models of iPad (for simplicity - “generations” are shortened to a number) that are restricted in their ability to be updated:

32-bit devices (obsolete)

iPad1 - iOS 5.1.1

iPad2, iPad3 and iPad mini1 - iOS 9.3.5 (WiFi Only models), iOS 9.3.6 (WiFi+Cellular)

iPad4 - iOS 10.3.3 (WiFi Only), iOS 10.3.4 (WiFi+Cellular)

64-bit devices

iPad Air1*, iPad mini2 and iPad mini3* - iOS 12.5.7

iPad Air2, iPad mini4 - iPadOS 15.8.3

iPad5, iPad Pro (9.7"/12.9" 1st generation)* - iPadOS 16.7.10

iPad6, iPad Pro (10.5"/12.9" 2nd generation) - iPadOS 17.7.1

(*) obsolete

Newer models are all able to be updated to the current version - iPadOS 18.1 (17.7.1 optional)

• iPad Pro 13" (M4)
• iPad Pro 12.9" (3rd generation and later)
• iPad Pro 11" (1st generation and later + M4)
• iPad Air (3rd generation and later + M2)
• iPad (7th generation and later)
• iPad mini (5th generation and later)

FYI: Just within the last two months, our iPad 2 running iOS 9.3.5 stopped working with Netflix. Newer versions of the Netflix app will not install on an iPad 3.

The other issue your Mom is facing is that internet speeds in general on older iPads can be abysmal. How about some data?

This shows internet speed test results from my old iPad 5 (iOS 16.7.10) on the left next to our even older iPad 2 (iOS 9.3.5) on the right, both on the same network channel and about 12 inches from our router/modem (300MB/sec service), and in the same plane:

The obsolete iPad 5 is 8X faster.

Nether device had any apps other than Safari running. I used fast.com for the speed test, as it is about the only remaining speed tester I can find that still works with both iOS 9 and newer iOS versions.

I worry that your Mom will find using such an old iPad in today's web environment frustrating. It's hard to find sites the even recognized iOS9 and, when you do, you can practically time page load times with a calendar!