Quote from: Kade1985 on May 28, 2014, 11:09:24 AM
I don't even know. My sister is refusing to even call me Kade and claims, "Katie is your name, and that' what I grew up calling you I can't change it". More like she probably doesn't want to.
Therein lies your problem, I'm afraid. No matter what you say to your niece, your sister is going to insist on having things her way. And as soon as you leave, she may try to rubbish what you've said.

Your best bet is to offer a simple explanation in five-year-old language.
So if I were you, I'd take your niece to one side and explain to her that whilst most girls look like girls on the outside and feel like girls on the inside, some people look like girls on the outside but feel like boys on the inside, and that this is perfectly OK. Tell her that people who feel this way sometimes feel that they have to change their outsides to match their insides because it feels horrible to look like a girl but feel like a boy and it isn't possible to change who you know you are. Tell her that just as she knows she's a girl, you know you're a boy and you're just changing the way you look so that everyone can treat you like the boy you are - but that you'll always be 'you' and you'll always love her.
BTW, if your sister is married to her child's father, did she change her surname when she married? If so, I suggest you couldn't possibly call her 'Mrs. Whatever', because you grew up knowing her by her maiden name and you can't change it...