RE: The Sisters are not nuns... 

From the Sisters' website:

Why do you mock nuns?
We are not mocking nuns, we are nuns. We are very dedicated to our calling and our vows reflect our commitment to our community. Look at the work traditional nuns do. Look at the work we do. They minister to their community. We minister to our community. They raise funds for the needy. We raise funds for the needy. They are educators. We are educators. See any significant differences? The list goes on and on...
The Sisters' FAQ