Julia pretending to be Batwoman is a reference to the 1966 television show Batman (1966), where there were a couple of instances when Bruce Wayne and Batman needed to be in the same place at the same time. Since Robin was too young to pose as his mentor, it left Alfred the Butler, the only person who knew the Dynamic Duo's secret identities, to pretend to be Batman.
In the comics, Julia Pennyworth joined the Batman Family as a mission control with the code name Penny-Two.
The Rifle mentions his employer by name, Safiyah. She has a complicated history with Kane in the comics. In the comics, Safiyah Sohail is the ruler of a pirate nation called Coryana, who saves Kate's life during the middle of her post-coming-out trip around the world. Kate and Safiyah become lovers, but they ultimately part ways when Kate accidentally carries a deadly disease onto the island, and Safiyah blames it on an innocent man. Years later, Safiyah has become a leader of the Many Arms of Death, a terrorist organization with reach across the world. Kate tracks down Safiyah, who has apparently kidnapped and drugged Beth in order to bring back the "Alice" personality. Alice then becomes the leader of the Many Arms of Death, and Kate and Julia have to stop her.
Julia dressing as Batwoman to convince Sophie that she is not Kate is similar to Damaged (2012) where Diggle dresses as the Hood to convince the police that Oliver is not the Hood.
Julia mentions how Bruce kept "Dino" picking up a T. rex model figure, a reference to the comics and other versions of Batman where he has a giant animatronic T. rex statue in the Batcave as a trophy, which first appeared in Batman #35 (June, 1946). It was a robot that Batman fought during an early adventure in Murray Wilson Hart's theme park on "Dinosaur Island".