Bettyg, Athabasca is a great way of boosting your GPA. I completed my undergrad many years ago and have been taking Athabasca courses intermittently throughout my career, they have all been included in the GPA calculation. You have to make sure that the courses you take are not Introductory level, other wise, they will be included.
Depending on your GPA and the University you are applying to, it may take a while to increase your average, but Athabasca is a great way of doing it. Doing an online BSW is another option, although this would take more time.
Good luck!