Could create daybed/seating area.

Layer rugs.

Boho type curtains.

Plug in wall sconces, etc.

Plants.

https://www.wayfair.com/furniture/pdp/east-urban-home-2-door-accent-cabinet-eunh6715.html

Nightstand.

https://www.jossandmain.com/furniture/pdp/rushville-3-drawer-nightstand-ando4624.html?piid=19070824

Chairs:

https://www.overstock.com/Home-Garden/Living-Room-Chairs/2737/subcat.html?featuredproduct=30537659&featuredoption=55021533&kid=9553000357392&ci_src=17588969&ci_sku=35381328-000-003&cnc=US

End table and/or coffee table.

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And your daughter should pick her own art/posters, etc. Etsy.com is a good resource for art - all kinds, including original paintings.

heres a few ideas for inspiration... a few boho characteristics to me would be layered rugs, layered patterned bedding, rattan, neutral colored walls, a natural wall hanging. I would focus on maybe one of those aspects so there is just a touch of boho with primarily modern furnishings.

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I think that you and your daughter need to collect inspiration pictures.

The new wall color will be key, or better yet, the bedding would be a good jumping off point.

There are lots of ideas, on-line, for decor accents to make a Bohemian room: macrame, baskets, rug, etc.

I would like to call your attention to the your daughter’s bed placement and wall/ceiling. Paint the walls whatever, but paint the ceiling and the angled wall a different color.

Making a canopy will set the stage for your daughter’s design.

Perhaps vanity next to window, bed and nightstands on long wall, desk on wall on right side, seating under window with her white rug, and her bookcase laid horizontally on slanted wall and decorate the top. Don’t forget some fun lighting

One decor combination below but it may help her decide if she searches any combination of the term boho bedrooms on Pinterest. I would suggest white walls as a calm backdrop and let the accessories be the main feature.

Modern boho

Boho

Boho chic

If your daughter tries the bed on wall facing window, you can also try a tall divider screen on right side of bed - to create a wall and soften ceiling slant.

How old is your daughter? Modern chic and Boho are two different things. Is All the furniture is staying? It isnt what is really considered "Boho". If your daughter is older I would assume that means old enough to choose the colors? I think a calming color on the wall in a white or blushed neutral would be nice. I think you need to look at Inso pictures and decide if she wants modern and chic or Boho and what those terms really mean to her. A lot of Boho rooms have mid century modern elements in them so perhaps that is what you mean? If so the desk and vanity are not the right style. Here are some more Inspo shots to help her narrow down exactly what it is she wants

also to share some ideas of what can be done over the bed with the sloped ceiling.