The artist is still selling originals on her website. One has a listed price of $1500, so they're not worth too much. I'm guessing there is a very limited market for paintings of Native Americans and horses by a Scandinavian woman. OP's best bet maybe just ebaying it off.
Maija the artist should paint Star Wars stuff. Instead of Indian women cupping their breasts, she should learn to paint Slave Leia. Instead of wolves and horses, she should paint Ewoks and Taun Tauns. There's a much bigger audience for that stuff. I just paid $2500 for some Star Wars original art from a comic con. Seriously.