salix

I haven't been recently but there were some Willow statues related to fishing in a seafront garden at Rhos-on-sea.

...pruner's..

I gathered up some willow clippings when a local willow structure was being pruned (with pruners permission) stuck them in the ground at home and they've all grown.

Willows do indeed sprout from almost anything. I remember seeing a willow gate post that started sprouting once!

As J52 says. They have planted a living willow structure at GS's school, just by putting bare willow rods into the ground. They are growing nicely. Similarly, there is a living willow fence at the playground in our local park.

Willows do really sprout easily from 'sticks'. I bought a willow fish sculpture, on a rod, put it over the pond and eventually the wind blew the fish away.
The following spring a pretty little willow was growing by the pond. It was the rod bit that had rooted!

The salix was in memory of their mum, another plant won't do. I would suggest trying cuttings as suggested by J52, and if that does not work perhaps plant a new plant of the same variety in memory of mum - not quite the same as keeping the original but better than trying to move it and watching it die.

Salix needs a lot of water, that's why they seem to thrive best beside streams and ponds.
They grow very fast as well, so need root space. I agree with others, a pot isn't such a good idea.
If you want to use a planter try one of the miniature acers, or small evergreens.

If it has been in the ground for eight years the rootball will be pretty large. Moving it into a planter could be a problem. If you have to move it, it would probably be happier in the ground.

A Salix is a willow and they can easily be increased by propagating. Just cut off about 10 inches of a new stem and plant in a pot of compost, keep damp and it will soon root. I'd do several around the edge of a large pot.
You could try and move it, but I doubt it would be happy and survive. It would best be done in winter when the tree is dormant.

IT may "live" in a barrell but it won't be happy for long and will soon look distressed