The following article contains spoilers from The Flash #786, on sale now.
Irey West's friendship with Maxine Baker, AKA Animal Girl, has caused her to have something of a rebellious streak, but The Flash #786 (by Jeremy Adams, Amancay Nahuelpan, Jeromy Cox, Peter Pantazis, and AW's Justin Birch) reveals that this isn't the only thing that has come by way of their friendship. After encountering each other while helping the rest of the heroic community during Dark Crisis, the two parted ways, but not before Maxine mentioned meeting at an undisclosed secret hideout.
This also opens up a number of possibilities for the girls. For starters, it implies that there will likely be a flashback story about how the two acquired the hideout. More interestingly, this begs the question of exactly what kind of hideout these two could have. Irey and Maxine are still children, and it's doubtful that their parents would have just given them a hideout, making this an intriguing mystery.
Additionally, Maxine's casual mention of the place implies that the two have had their "secret hideout" for a while. However, the location may not be that much of a secret. Maxine mentioned it it in front of Irey's brother Jai, implying that he is already in on the secret. A reason for this could have something to do with him feeling a need to keep an eye on them, as he has expressed a dislike for the two running off together without him.
Another question concerns exactly what the hideout is and what it entails. These are still children after all, and what they consider a hideout is sure to be colored by their childhood perceptions. This means that their meeting place is sure to be nowhere along the lines of Superman's Fortress or Batman's Bat-Cave. The hideout is most likely a treehouse or something similar, although with their level of ingenuity is is entirely possible that they may have found a way to create something entirely unique.
Irey West is destined to become more powerful in the speed force than her father, and Maxine is the current avatar of the Red. This gives both girls the potential to be very powerful, and it is quite possible that their hideout could somehow be connected to their powers. It would not be beyond the realm of possibility for Irey to create a secret pocket within the speed force that only a select few people would be able to even access. At the same time, Maxine's powers may have led her to a mystical animal sanctuary of some kind.
Ultimately, this throw away line creates a number of opportunities for the girls. It sets up new stories for them, and also invites stories in which their powers can be explored more throughly. Most importantly, it shows that they are dedicated to establishing themselves as heroes, even at the cost of keeping a few secrets from their parents.