Tracy, her name will be Tracy, because of the thanksgiving episode, a girl says, "my name is Tracy" and Ted said, "that"s how i met your mother" which made the kids freak out, so her name must be Tracy. She plays base in the band at robins and barneys wedding, that is how they first meet, also it was raining in one of flash-forwards, so she would have the yellow umbrella. she will be blond, that has been implied several times.