"Everyone who came with me. They crossed the sea for me. They fought for me. Only to have their arms taken," Roderika says when you first meet her. "Their legs taken. Even their heads... taken. Taken and stuck to the spider."
Roderika, like any other Elden Ring NPC, is kinda creepy, and when you first meet her, she has a terrifying story about how she's the lone survivor of a band of travelers who have been grafted onto a "spider". She then hands you some Jellyfish Spirit Ashes and off you pop on your adventure to hopefully not join her comrades as a mangled mess of awkwardly attached limbs.
You might've simply moved on with the ashes and forgotten all about Roderika, which many Reddit users appear to have done themselves, but there's more to her story as many in the thread have shared. You can find a pile of ripped-apart corpses left behind in Stormveil Castle, right next to a Grafted Scion miniboss. Here, you'll get the Chrystalids' Memento, an item you can give to Roderika to unlock her shop where you'll be able to upgrade your Spirit Ashes.
Given that we find this item by a Grafted Scion and a pile of corpses, it's likely that these are those very same traveling companions that she mentioned. Good news is we didn't join them, and with that item, neither will she. Instead, Roderika will travel to the safety of the Roundtable Hold. From here, you can talk to Smithing Master Hewg and convince him to take her under his wing as an apprentice. Return after a while and she'll be by his side, ready to upgrade your Spirit Ashes.
There's still the mystery of who this entourage was, but if you dig deep enough, there are answers. As DirtyRanga12 says, "She was the leader of a group of Tarnished trying to claim Godrick's rune. Her rant is about regretting sending her followers to their deaths and not dying with them." LongBarrelBandit added, "She also references Varre when talking to the player. So I think she may have been directed towards Stormveil by Varre, just as we are at the start."
Going further, some players discovered that she "was an exiled 'unwanted' royal relative from across the sea, who came with a retinue." This is found out through her hood, which has the description, "Worn by expatriated royalty... Such cloaks were gifted to those who departed on journeys without specific orders, to faraway lands from which they would never return... Roderika never once saw the guidance of grace."
Like many characters in Elden Ring, Roderika's story is tragic, but we can help her to find purpose and a way to channel her attunement with spirits for 'good' (or for our benefit, rather). It's all a little selfish, but that's par for the course with Tarnished. Regardless, we can at least avenge her traveling troup.