Hello ,I will suggest a Gardenia

Very good to purified air and very goo for a good nice sleep

Sorry ,I have problem whith this site...you will need at least 5 hours of indirect light

At least 5 hours of indirect sun light ,and to keep it moist ...not the easyest plant but definitely worth it .
Hope this help

Sansevieria (snake plant). It's a low light plant and classic for this purpose.

'According to NASA research, Sansevieria species purify the air inside the home by removing formaldehyde, xylene, and toluene. These chemicals are commonly found in carpets, upholstery, glues, dyes, paints and other building materials.'
https://www.postbulletin.com/life/lifestyles/growing-concerns-let-s-clear-the-air-on-snake-plants/article_c9985275-dad6-5060-84ee-77069cdf8d41.html

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I would find gardenia perfume overwhelming in a bedroom but its all a matter of what you like. But few scented plants flower all the year round so why not have something tolerant like a peace lily that doesn't like direct sun, and have some pot pourri for the perfume?
Or maybe she would like the smell of a scented geranium - the leaves smell all the year round (I like the smell but not everybody does so best check it out before buying...)
They don't have the big showy flowers of most "geraniums" but they do flower and are very easy to care for. They like a sunnier window sill than the peace lily.

If you put plants that clean the air into Google you'll find a list but they aren't scented - I can't think of anything else that will do both jobs all the year round.

Some of the "Creeping Charlies" (Plectranthus species) have a light minty scent.

I had a Gardenia and the perfume was so overpowering I couldn't bear it. I'd say get a Stephanotis but I've just managed to kill that off a year after it was given as a Mother's Day present! What about Hyacinths while they are in season or Jasmine?

I have a couple of cyclamen in the bedroom just because they are pretty. however all plants will use oxygen like you do during the night and release carbon dioxide. that was why they were always taken out of hospital wards at night.

Gardenia was bought 5 years ago for my mother that suffer from anxiety after the advice from her GP.....she does sleep very well since!