My only rationale for her telling, is that if she makes it long enough for the loved ones to come rolling in, and Eddie George comes running through the camp, and somebody recognizes him, she would be screwed. Now she said it early enough in the game that it looks as if she never tried to hide it. Could work out for her in that instance. Otherwise, you'd think she would have had to come into the game with that lie ready.
As for Candace and Carolina recognizing her from SWV, they have sharp eyes on them if that is true. SWV was over 15 years ago and at this point quite a few pounds ago for Taj (I understand she's working off some baby weight). Looking at her face (and her nose is distinctive) if you watched SWV back in the day they could have recognized her, however, I don't think that many people would have made the connection.