How much do I miss sending her back to Athkatla?

So I went to Spellhold with all my party members, which includes Nalia. She’s the one I was planning to replace once I reunited with Imoen, but then I found out that Nalia will just stay behind if you dismiss her.

I didn’t want to lose her there for the rest of the game, so I sent Imoen back to the Copper Coronet.

Will I miss on a lot of important stuff with her? Will I still get to at least do some questing with her before the end? Kinda messed that up but I’m having too much fun to go back to the previous chapter.