Buffy in Season 6 takes over her mom's gallery even though she doesn't have any degree. She gets into art and photography as a type of therapy and displays her stuff (along with the other members of her art/photography classes) in her gallery.

What I currently have in mind is that in order to make money, she opens the gallery up to an Art Therapy Group and possibly also allows other people to host classes: yoga, addiction recovery, etc.

Since she's short on cash but provides the space, Buffy will partake in the classes and finds a healthier way of dealing with her depression. Buffy also develops an interest in photography and begins to make that her career, using the gallery to display her photographs.

Maybe Spike can become her muse when she gets into photography? You know how he offered to be a model in Restless!

Highly recommend having Tara and Anya partake in the art therapy stuff as well.