If Alice Eve is playing a hero or ally in Iron Fist Season 2, there’s not a lot of suggestions being thrown around the web as to who she may be.
There aren’t a ton of notable female heroes in Iron Fist lore that haven’t already been introduced, although Danny Rand does have a half sister in the comics named Miranda.
Given that, it’s highly unlikely this is who she’s playing, but anything’s possible.
Eve and actor Finn Jones have a somewhat similar appearance and could pass for siblings, so there’s a chance that’s who Marvel intends her character to be.