Stefia,
The answer to your question depends on where your path in TG life is going. The best thing is to say is "We will just have to be extra careful" if she has reservations about secrecy safety.
But if your telling her because you want to shout from the rooftops "I am all that is STEFIA", then you will obviously need more of an explanation for people when they meet your girl side.
I wish i could help more but, am not in the position to give you advice on this avenue of TG Life
Trying to help anyway tho,
-Donni-