The following article contains spoilers from I Am Batman #12, on sale now.
Jace Fox's team-up with the Question (aka Renee Montoya) in I Am Batman #12 (by John Ridley, Christian Duce, Rex Lokus, and Troy Peteri) was an enlightening experience for him and readers. The Question wasn't just helping Jace in his investigation of Anarky's death, she was also advising him on how to run his operation. Chief among those suggestions was whether he needs a partner or not.
The Question believes that he should have a partner who can operate with him out on the field along with the people who currently work with him behind the scenes -- like Vol and his father, Lucius Fox. He needs someone who will challenge his perspective and offer alternative solutions for any problems that may arise. The issue itself offers a number of possible candidates for this while highlighting how Jace is always more effective when he asks for help.
Among the candidates for this theoretical partnership would be the Question herself, and surprisingly, Jace's youngest sister, Tiffany. Starting with the Question, it seems like a logical choice, both have similar goals, are trained fighters, and she has the investigative skills that Jace lacks. She would be an excellent way to cover any weaknesses he may have as the new Batman. However, the Question most likely wasn't referring to herself when she advised Jace to consider a future partner.
When questioned by Vol about whether she would be a recurring ally, she seemed hesitant to give a definitive answer. Aside from the fact that both vigilantes are still trying to get a feel for one another -- Renee has not made up her mind yet on if she wants to move to New York to become its new commissioner. So, her hesitation might not just be about trust, but simply the fact that the commute would be too much.
Then there is Tiffany. It cannot be a coincidence that the same issue that discussed Batman finding a partner also happened to have snippets of Tiffany's personal life. In her side story, she wrestled with wanting to use violence to protect someone who was being mugged. What's clear about the youngest Fox is that she's having a hard time finding satisfaction in how she currently helps people. She has always been incredibly smart, even by the standards of her exceptional family. It makes sense that she wouldn't feel challenged enough by her life as it is, but it stems from more than just thrill-seeking. Tiffany simply feels like she isn't doing enough.
In that regard, she is very much like her oldest brother. Jace became Batman because he wanted to do more to help. If Tiffany is feeling the same way, then she may end up becoming a vigilante herself. She certainly fits the bill of someone who would challenge Jace's perspective and force him to consider new ways to tackle a problem through more than violence. In the past, Jace has benefited greatly from the support of his allies. Having another hero on his side can only help his cause.