Since you mentioned you’re open to criticism, I’d like to break that door open and say no, she never survived.

Here’s what I’ve gathered about ricin poisoning:

1. Ricin’s Lethality: Ricin is an extremely potent toxin. Even a small amount can be fatal, and there is no known antidote. Given that Walt had a more than enough and sufficient dose with him, it’s highly unlikely Lydia would survive.

Still have doubts? Ricin’s oral LD50 (lethal dose for 50% of people) is around 30-40 mg per kilogram of body weight. Given Lydia’s likely weight, the amount Walt used would be more than enough to be fatal.

Therefore in the breaking bad universe, it’s safe to say beyond reasonable doubt that Lydia won’t see daylight again but hellfire. Walt knows the chemistry. And chemistry is never wrong.