Hey, remember that time Suyin saved the Avatar Cycle?
Suyin's handling of the metallic poison situation is among some of the pettier things that fault-finding fanatics within the ATLA/LOK fandom tend to hurl at Suyin, which genuinely baffles me. Maybe I am overreacting, but it often feels less rooted in any genuine criticism of her character rather than an avenue to use some thinly veiled microaggressions to excuse their issues with her at best or exercise flat-out hate towards her at worst.
"Smh she didn't even get it all it out"
"Lin would've got it all out"
"Toph just crapped on her"
General comments like these often carry a negative connotation, focusing more on Su's failure to fully "heal" Korra. Something that I feel is missing out on the deeper intricacies of the matter, which I'll get to in a moment. There's also this very peculiar sentiment that the poison was all that held Korra back when it was actually a combination of factors such as the brutality of the fight itself and the lingering PTSD that stemmed from her overarching doubt and fears over her role as the Avatar. All of these factors, along with even inhibiting the poison within her bloodstream in the first place, is what crippled Korra for years.
Not having it all out or not, seeing as how Korra still had issues even after removing it all in Book 4.
Speaking of bloodstreams:
Let's discuss Suyin's prowess as a metalbender. Firstly, it was a miracle that she was even able to get out as much as she did, despite Zaheer deliberately prolonging the fight with Korra so that the poison could be further entrenched in Korra's body and her bloodstream. Who knows, maybe if Suyin had gotten to Korra immediately, she would've likely gotten it all out, which is something I hardly see get mentioned.
The complicated nature surrounding the poison itself is another issue: Not only was the poison fluid in nature, but with it being metallic, Suyin had to actually perform the double duty of carefully finding the traces of earth within a liquid substance within someone's bloodstream in a very quick and precise amount of time because Korra could very well die at any moment. That is A LOT to consider, and she still managed to do a good enough job to save Korra's life and, you know, the Avatar cycle itself. It's also neat that Suyin uses techniques similar to waterbenders to navigate the poison out. This highlights the level of her precision with the element and the sheer amount of elegance that Suyin has with metal bending.
It exemplifies an understated quality to her character in how she's spent much time exploring the more intricate and creative ways to apply her bending that isn't just combative.
And you all better thank her every day for being that way!
Okay, I’ve been thinking about this for a while but it’s always bugged me how Toph’s oldest daughter looks like Zuko and her youngest daughter looks like Sokka (a commonly accepted head cannon) and how that must’ve caused a lot of drama, but I just found out today that Zuko raised Izumi by himself like he never canonically married anyone and then I was like oh cool, so he got a surrogate or some thing and then I connected the dots.
So Sokka never marries anyone. Zuko’s never marries anyone. Zuko and Sokka spend a LOT time with each other up until Sokka dies. Zuko has a surrogate child… Toph’s children looking oddly similar…. it’s too coincidental for me. 
So yes I’m insinuating that they were gay and Toph was their surrogate.
Just look at them!
And it makes sense why Toph never told Lin and Suyin because their lineage would be a massive safety issue concerning the amount of assassins that were after Zuko. I completely believe Toph would hide that from them for their safety.
Lin and Izumi look almost like twins! Toph probably wanted two kids and Zuko and Sokka wanted one and so Toph offered to be a surrogate so they could both have kids. Boom.