I'm fairly, 89% certain Sundew has a Girlfriend, and her name is Willow.

Think about it.

      We all know who Willow is;

* she saves Turtle and Tsunami in the Epilogue. (Aka she's METAL like Sundew)

*We also know that she knows Sundew- there's a part where Sundew is about to mention a name but cuts herself off: "Wil-".

* we know that she's not Sundew's sister- otherwise she would've been mentioned due to her family's role in the missions that she performs.

*Sundew was guarding the information about her like it was a big secret while she hasn't been afraid of sharing names before, so therefore she can't just be a friend.

      We also know due to the whole Anemarin and Blue's Moms things that Tui has lesbian and gay characters, so don't do that 'oh but you're being a dumb overexcited fangirl' thing. Just don't. There's PROOF.