Bringing Life to an Old iPad?

Dear Wife has a favour to ask: she has an old iPad that she wants to use to watch YouTube videos on various hobbies and topics of interest. Since security updates stopped long ago, no financial or sensitive stuff on the old iPad (she has a new one for that).

It's seems like the native Safari browser can't handle it. On other platforms, I would be sniffing out a different browser. But I don't know the Apple ecosystem.

I'm a tablet-o-phobe in general ("give me laptops or give me death!") and I use Windows and Linux, so it's a climb up a long ladder to figure this out.

Any i-heads out there who can help me out?

(EDIT: OS version 12.7)

I’ve put my ipad mini 2 (also 12.5.7) on charge and will get back to you tonight.

There was a method of force updating older ipads but it required using a second Apple device.  

More info: she's been using the YouTube app.

I've suggested that using a browser with an ad blocker might solve the problem. Ads bog down older machines to the point of unusability. Chrome browser is currently installed and we'll try that first. I hope there is an Apple version of Ghostery I can add.

And yes: OS is 12.5.7.

And nope. This’ll require more extensive digging, that I may get to it on the weekend but not right now.
Just sailed into Madagascar and there’s a lot to do and on my mind.

So Firefox (version 36) plays vids but I haven't looked for a way to block adds yet.

If you haven't already then hubby suggests blocking future software updates once you get it working properly. Operating system updates eventually make older hardware obsolete.
You may still be able to install an independent security system like Kapersky for safety.

For what it's worth, I dug out an old iPad2 that we had laying about.  Unfortunately, I can't seem to find where it shows the current version of Safari, but the OS is 9.3.5.  That browser is the only way that I access YouTube on that iPad, .... But I'm surprised at how well it does YouTube videos and the only 'hiccups' are from the iOS wanting me to sign in with Apple ID.  Our ISP is only moderate as we live rural...no superspeed access here. Don't know if this is of any use?

Opera looks interesting. Supports OS 12x. Ad blocker built in and VPN.

Adding to the list:
Ghostery Private Browser, built on Firefox.