I wouldn't, I think our defences are there for a reason, if you want to go to the group you'll find a way to manage it, which might take you time to work up to but means you'll be taking care of your own needs. I'd be especially wary given your previous (current?) experience of having a T with very poor boundaries where there's been issues of her fostering dependency. Going to the group alone may be difficult and uncomfortable but if it's something you really want to do, overcoming the discomfort for yourself would be incredibly empowering.

What happens if someone asks you who your "friend" is either at your first meeting or later. You'd be lying to call her a friend - which isn't great in a therapy group. I too like to see mine, pay her and know where we both stand.