So the basic premise of Mrs. Payne here is that she is the worlds most unnecessarily jacked personal assistant. I haven't even worked out who she works for.
I was thinking about Mercy Graves (Lex Luthor's driver and personal assistant in the DCAU) and how she does a lot of things that are not part of her job description, as an inspiration for Mrs. Payne.
I don't want her to be evil though so maybe she works for a rich hero, and does the actual heavy lifting whilst they just take the credit.
Maybe she strikes out on her own one day. It's fun to imagine things :)