Sooooo, yea. I've come out to my Nanna. I didn't wake up today thinking I'd be telling her, but after the experience I had at the salon today (see my thread in the Transgender Talk forum), my confidence has been through the roof and I kind of decided a few mins into our Skype call to tell her.
Things went almost exactly as I expected, she is accepting and had plenty of questions. She even had some advice about other family members (which was 'none of their business!'). I even showed her some photos of me from the salon and she was very surprised. She said if she didn't know otherwise she would have never known it was me, and definitely wouldn't think I was male.
I'm very happy. This is a first step on the road to coming out. Didn't expect it to happen so fast since accepting myself if I'm honest. I've asked her to arrange with my Mum to Skype me on Wednesday so I can tell her without my Dad around, though she won't mention why. I live abroad in Japan right now so aside from email or a letter, it's the only way to get in touch with them. And I'd much rather tell her as face-to-face as possible. My Dad is going to be the biggest hurdle and since I'm going to be moving back in with my Mum and Dad (at least temporarily), things may get a bit tense.
Otherwise it's been a very eventful, happy day!