Far, if I were you, I'd try to make it all seem a little lighter; I'd maybe buy a garish, plastic, toy phone and keep it with me to represent T and calling her. If you think about it, even her saying she will be there on the phone isn't the real thing, her being there. So, I'd find something that reminded me of her and her promise and hang on to that as if it were the actual phone calling/promise. Maybe put masking tape or something on it and give your T a magic marker and have her sign the tape, "I will be there when I say I will, T".