I was actually think it might be cool if the MCU version of Power Broker would be Betty Ross(,Thunderbolt Ross'daughter. Not sure why she'd take an evil turn. We haven't seen her since 'Incredible Hulk.' I also don't think Liv Tyler has ever played someone villainous before. However, since Betty was "dusted" during the snap, according to the Russos, she can't be Power Broker, because she wouldn't have had time to consolidate power since FATWS takes place 6 month Hulk snaps everyone back. Though maybe she'd been conoldating power for about 10 years. Keep in mind it's about 2023/24 in current MCU time.