What is this?

I would say it’s some sort of national costume..

Do you have a museum locally? They might be able to give good advice.

Maybe Austrian, from the Tyrol ?

A costume museum?
An amateur dramatics society? (There's very nice Gransnetter on here who is involved and who is extremely helpful and appreciative😉).
A local Dancing School?

Looks like a dirndl outfit ... worn traditionally in Germany..

I agree it looks like a dirndl. German, but I'm wondering if they wore them in Austria as well?

It's lovely and looks in excellent condition. I would ask a museum.

Don't throw it in the bin!!

I had a lovely Swiss girl (Heidi?) dressing up outfit, embroidered with a waistcoat, blouse and skirt, when I was a little girl. I loved it, apart from the straw plaits which stuck into my ears. Unfortunately, my mother was a great declutterer, goodness knows where it went.

You could sell it at auction. Its age and provenance should command a good price.

It looks Austrian. The flowers look like eidleweiss.

I think it could possibly be Norwegian, particularly with the striped skirt.

I'd say possibly Austrian.
I agree a local dance school might like it especially if they do BTDA competitions.
It's lovely.

My immediate thought was Austrian too - from Tirol
The Edelweiss on the apron certainly suggest that and although the style is very like a German Dirndl, and I know that every region or “Land” has its own variation, I also think the hat suggests Tyrolean.

Looking at the age of your mum is it possible that this was a gift to her at the end of the Great War? If so then Germany or Austria seem likely places of origin. There was also a trade agreement between the UK and Norway at that time and the Norwegian National Dress (Bunad) having been reintroduced in 1913 would have been a lovely gift for a sailor to take home.

Please pass it on to a local museum who may be able to discover a little more about its origins. Such a precious outfit.

My thought was Austria too and that the flower was an Edelweiss

I think it's Finnish. I used to collect costume dolls and had one from Finland. If you Google Finnish national costume you can see examples. But what to do with it, I don't know. Maybe a dance school or children's theatre group?

why would you throw it in the bin ??
rather than give it to a charity shop at least.
there is an oxfam shop in london, ? drury lane, that specialises in vintage clothes.

Polish perhaps.

have you tried googling the picture ?

It’s lovely, I thought German dirndl but could be Austrian or Swiss. Certainly European. Please don’t throw it away, it’s an heirloom!

Don't bin it !

Sell or donate it .

Antique adult versions make surprising amounts of money .

I'm almost certain that it's Norwegian because of the shape of the bodice and the border. It's also the right colour .

grannyactivist also thought that it might Norwegian .

It looks like Norwegian national dress to me.

I agree with ixion that a local dance school, amdram society or museum are all good suggestions.

I just googled images of national dress and what is striking are the similarities.
It could be Romanian.
All useful for a dance group or suchlike.

As others have said don't throw it out . Post the lovely photo onto a local site, Gumtree perhaps, with a respectable price and see if you get some interest.

There’s a story to that outfit I would have to explore. Have you done your family tree? That’s a start, it must have meant a lot to your mother to have kept it.