Tell her that you value her opinion and are grateful that she wants to help with the planning as much as possible, but that she's already got to have HER wedding, and this is YOURS and that if she keeps pressuring you that you'll elope and she wont be a part of it.
My mum is ESFJ. I have to call her on her emotional BS a lot of the time to get anywhere. That being said, i love her like crazy. She just annoys the hell out of me sometimes.