The following article contains spoilers from I Am Batman #13, on sale now from DC Comics.
While Jace Fox's early days as Batman have been the central focus of his series, the story has also focused on the other members of his family. In particular, Jace's younger sister, Tiffany Fox, has gotten special attention as readers got to watch her mounting frustration push her to take extreme action. This all culminated in I Am Batman #13 (by John Ridley, Christian Duce, Eduardo Pansica, Julio Ferreira, Rex Lokus, and Troy Peteri) when Tiffany decided to help keep a friend from returning to a life of crime by putting on a makeshift costume to fight the gang trying to recruit her.
While Tiffany's outfit is far from a hero suit, and she doesn't have an alter ego name, it seems as though the story is setting her up to become the latest Robin. It makes sense in its own way, Batman always needs a Robin, and Jace's story as of late has been hinting that he needs a partner who can challenge his perception of things. This fits Tiffany to a tee, as in their civilian lives she regularly forces Jace to consider other people's perspectives. However, the question now is whether this is a one-time thing or not, and if not.
For months now, Tiffany has been struggling with her move to New York. As an especially gifted member of the Fox family, she has been frustrated with how little she has been able to do to help others due to her age. When she hasn't been trying to find her new thing, she's also been working out to learn how to protect herself. Undoubtedly a reaction to all the danger she and her sister have been through while in Gotham. This all came to a head when her friend, a reforming criminal, was approached to rejoin the gang that got her in trouble in the first place.
Not content to stay out of it, and not trusting that anyone else would help, she put on a makeshift suit and went in pursuit of her friend. What Tiffany's exact plan is has yet to be revealed, but now that she's on the streets it will undoubtedly come to the attention of her older brother. Her parents will probably contact him to help search for her, leading Jace to find her all suited up and fighting crime her own way. There's an excellent chance he'll try to shut down any further vigilante activity on her part. Aside from the fact that she's a child, Jace has made it clear that he has his criticisms of the original Batman, and would likely not want to replicate anything he does. Especially something as morally ambiguous as having a Robin.
However, if Tiffany learns the truth about Jace's nighttime activities, then she could force him to let her help. Jace might not be okay with her being in the field with him, but there is no denying that Tiffany is brilliant. She might get relocated to the Helix, helping Jace out with more technical stuff, or even detective work. He's admitted to not being a very skilled detective and Tiffany's intellect could compensate for that.
Alternatively, she might find some way to become his partner in the field. If so then Batman would have a new Robin on his hands which might lead to an interesting meeting between Tiffany and Damian Wayne, who would likely be less than happy that someone else took up the Robin mantle. On the other hand, Tiffany does not seem the kind of person to use another's name, she's more independent than that. If she does become Batman's partner, chances are that she'll make up a new identity for herself, truly finding a purpose and making a mark in the city on her own.