Welcome to GoY Mossa.
This is a good time of year to take stock from your Mum's garden.
Most perennials will move quite happily at this time of the year, plant each one in a pot big enough to accomodate the root system, stand the pot in a similar position in your garden (ie. sunny, shady, exposed, sheltered, etc) and keep an eye on them over winter.
Some may be too large to move easily, perhaps taking cuttings would be a more viable option.
You may find some have set seed so you can collect the seed to sow now or next year, depending on the parent plant.
I did this with many of my parents' plants when my Mother died, and they have given me a lot of pleasure in the intervening 3+ years. I hope you find the same.

Personally i would dig them up with as big a root ball that you can manage and then replant them in your own garden asap

Hi, I agree with Anchorman, they will be far better of planted in the ground if they're hardy perennials, frost can get at the roots if left in pots, but in the ground it can only get at the top, Derek.