Surprisingly stubborn Iris may have been, but she didn't have any sort of the physicality that Selina did. Her life had always been soft, and it had caused her problems more than once since she'd left home those several years past. Though she did her best to stay strong and steady, the shove from Selina easily pushed her aside. She didn't want to be "taken down" at all, but much less with Gus watching. Selina was right about that much. It didn't mean that she was going to roll over without a fight, though. She caught her balance with the help of her grip on the doorframe and followed as closely as possible.
Close enough to reach out and snag one of the straps on the back of the straightjacket Selina still wore. She planted her feet and did her best to pull back. She knew it wasn't going to do much, but she had to fight back somehow. The security system panel still blinked its silent warning in the livingroom, but she didn't know what sort of response (if any) it would receive. 'What to do if someone from Gotham comes to steal Gus' wasn't something she and Luke had discussed.