Good store to buy a tough, inexpensive duffle bag/luggage in South London

I would think that if she has done that much shopping, she has seen or been in a store or 2 that sells luggage or bags. I would think this is not a 'problem' you need to solve.

A search for 'luggage in London' produces literally millions of responses

Glad to hear her rash problem got controlled

South London is a quite large place.

Surely she will be passing places which sell such things as she travels around, perhaps near wherever she is staying, or even more likely wherever it is that she is studying. I don't know her but I would trust most 20 year olds to be able to solve that one.

There are all sorts of places selling luggage to people heading off on holiday so there should be plenty of choice.

If she doesn't find anything good, there are Samsonite stores around, although probably easier to find in London, and Antler stores, although again more likely in London than Croydon (but check the Whitgift Centre, maybe Sports Direct or JD Sports) or Thornton Heath or Peckham.

I bought a big light suitcase for cheap at a place called Mr. Luggage in Hampstead, but when I went to look for the link, it came up as reported as closed :(

This should work :)
https://store.ricksteves.com/shop/p/nylon-tote-bag

If your young traveler is old enough to study abroad, then she is old enough to determine if she needs extra luggage. If she does need one then she would be able to find something on about every block. Even the small stores that sells miscellaneous items (candy, biscuits, aspirins etc.,) along with some souvenirs sales small luggage.

Blacks and Millets are two different store chains that specialise in outdoor gear.

Thanks for all your responses, and for the store recommendations. We found out that American charges $200 for the third checked bag ... ($100 for second). So I'm thinking a better plan would be to get a big tote that could be put in the overhead bins, that would hold your purse inside as you boarded the plane, along with a backpack that would go under your seat. Then remove your purse after you board. That way you're boarding with two items, having checked two bags. Paying $200 for a third checked bag ... Going to try to avoid that! Thanks again!

There's always TK Maxx, which seems to have a number of metro London locations. Why they changed one letter from TJ Maxx I don't know, but it's the same kind of inventory as their US stores.

When TJ Maxx opened it's first store in the UK nearly 25 years ago there was another chain called TJ Hughes. To avoid confusion the name was changed to TK Maxx.

TJ Maxx is my favorite store here to buy discounted luggage and purses. I will mention that to my young traveler. I didn't realize they were in London. Thanks so much!

Emma, the Southwark area ...

There aren't actually any directly in the Southwark area. The nearest, if she goes north of the River into The City is at TK Maxx Gracechurch Street, 33 Gracechurch Street, EC3V 0BT, near the corner of Fenchurch Street, behind The Monument.

There literally dozens of them in the London area. Where does she travel to for her course? Maybe she goes past one or many.

Nigel, I will give her that information on the closest one. She goes all over on the Tube and the trains so I'm sure she will get to one. Thank you so much!