I would love to see Una get her own starship command. She'd be awesome!
However, given Commander Ransom's line of her in LOWER DECKS saying she was 'the hottest first officer', it lends to the idea that she dies before getting her own command. (I kniw the line was an in-joke about how they are married in real life, but it is canon.)
As an alternative, because I don't want to see her killed off, I can see her taking command of a starbase. It worked for one excellent leader... can work for her, too.
The showrunners and Rebecca have hinted that she'll be given her own command. La'an being first officer to her would the happy story she deserves.