Ey there Dreamteam3,
I assure you that it's not a doppelganger. But even if it was a doppelganger, it's in your own dream, your own territory and your own kingdom. You have the ability to destroy it in a wink of an eye. I suggest You Continue to Lucid Dream. It's the main reason why you are here my friend. It's your passion and your goal as a lucid dreamer. Don't give up and quit just because you saw an ugly lady. I understand what you're feeling, the feeling of fear and agitation, but you must exert superiority and assertiveness in your dreams. All of the things you see in your dreams, are under your power. You are omega and all powerful in your dreams. So go out there, become lucid, and do everything you desire. And if that ugly lady have the guts to show itself again, vaporize it into thin air.

Hope this helps and motivates you