Should sissy have a "girlfriend"?

My sissy is feeling the need to express herself as she mentioned in her earlier post.  She would like to express to a "friend."  There is a particular friend, a BBW she's fantasized about serving even before we began down the road of a sissy/goddess relationship.  My question is, do my fellow goddess'/dom's allow their sissy's/wifey's to have "girlfriends" that have previously been romantic interests they wanted to play with as dom's themselves? 

I am having a hard time allowing this relationship and I think I have figured out why just tonight.  Among other reasons (like quite frankly a BBW is a goddess herself) because this BBW was a romantic interest before our change in dynamic and now I feel as though my sissy is subverting my dominance by wanting this BBW to remain in her life.  I want to give my sissy an outlet of someone to talk to because I enjoy very much being a loving/giving goddess but I just really don't want to give her this particular relationship.  I would be very pleased if she found a man she could talk to or a woman friend of my choosing that she could relate with female to femme/male but not this particular one.  I feel a bit silly.