Right, but Kalanchoe and Hoya both bloom, and Hoya flowers are very fragrant. Not a good choice for this person's allergies.
Btw, coleus also flowers for me here, late in the summer/fall. You can pinch and prune them to keep them from setting buds and just enjoy the colorful foliage, though.
That window actually has pretty good light. (but, your sanseveria is not getting much, around the corner there) You could hang a nice big plant - a Philo would be nice - in front of the left side so it wouldn't be in your way, or set a plant stand or table in front of it. A palm would be lovely, but they do flower, too. Also a good size one would be expensive.
