Since Esmar is non-binary, the term "sister" is not applicable. Sibling is the term which should be used.
If a Legacy series did happen, I wouldn't be surprised if the entire bridge crew outside of Seven, Raffi, Jack and Sidney were replaced with new characters. (I'd also make Jack either the ops or tactical officer, rather than "advisor to the captain" or whatever BS they made up for him at the end.)
I got bored and even though I generally dislike A.I. art, I decided to be a hypocrite and play around with an A.I. art generator and see if I could better visualize Kacey Rohl as Rachel Garrett. I'm actually shocked how much she fits the role.
I wonder what uniform they'll use. The classic monster maroon? The updated version from SNW? Or something new? And if it's the classic one, will they try to explain it, perhaps with Georgiou's time traveling?
While there's a possibility they might stick with the Monster Maroons, either classic or updated for the sake of memberberries, I also won't be shocked if we see a completely new type of uniform. We'll just have to wait and see. At the very least, I know whichever decision they make will not be influenced by the fact that TNG established the Maroons lasted for most of the entire Lost Era time period, from the TOS movies to about 10-15 years prior to TNG.
Legacy hands down. Later down the line Stargazer could be cool, but as an animated series. I would love a series or movie on the Rise of Kahless on Quronos or Surak on Vulcan, maybe a time traveling ship that protects and explores the timeline.
Voted Legacy. Bring back queerness now that DSC is ending. I'd love to see The Lost Era but I presume the artists would just redesign everything, from uniforms to gadgets to gear, like they did with the shows set in "The Cage" - TOS timeframe. We've already seen the modern take on the Monster Maroons. It wouldn't look like what we see on TNG-R. No thanks.
I voted Legacy. A Captain Seven series seems like a no-brainer. We had a chance to meet Jeri Ryan recently, and I told her exactly that. Her reply was "I know, right?!"