WARNING: The following contains spoilers for One Piece Chapter #1020, "Robin vs. Black Maria," by Eiichiro Oda, Stephen Paul and Vanessa Satone, available in English via Manga Plus and Viz Media.
Despite what Black Maria believes, Robin's faith in her crewmates has become unshakable, even at the height of the ongoing Onigahima Raid. In Chapter #1020 of One Piece, after her attempt at tricking Robin by using an illusion mist fails, Kaido's Tobi Roppo henchwoman attempts to hit harder by taunting Robin's role within the Straw Hat crew. More specifically, she targets her faith in Sanji.
After Sanji was captured by Black Maria -- also by using trickery -- she beat him to the point that he called out to Robin for help. This was all in a bid to capture Robin to force her to read the Poneglyphs for Kaido. While her plan partially worked, as Robin has indeed come to Sanji's rescue -- along with Brook -- capturing her has proven to be tougher than Black Maria initially thought. In an attempt to break Robin's trust in her friends, Maria comments that Sanji knew what he was doing by calling out for Robin. He knowingly and willingly led Robin into danger, then escaped after being released from Maria's web. She calls Robin the "baggage" of her crew and mocks Sanji for his apparent weakness.
Robin, however, counters these claims. She says that she is thankful that Sanji relied on her and that he is worthy of his bounty. She even goes so far as to call him the "Wings of the Pirate King." This not only shows her faith in Sanji but also her belief in Luffy's dream of becoming the Pirate King. She goes on to tell Maria that she could never understand how it feels to know that someone relies on her so much. Despite the situation seeming to play out in Maria's favor, at first, Robin never doubted the trust her friends have in her, nor the trust she has in them.
This is the height of Robin's development as a Straw Hat in One Piece. At first, she only held distrust towards them. She was quiet, only spoke when the moment called for it, acted distantly and rarely took part in the others' silly antics. Everyone she had met up until joining the Straw Hats would try to earn money by turning her in for her bounty. She even saw her life as Luffy's responsibility after saving her from execution at Enies Lobby.
Now, Chapter #1020 makes it clear that she finally sees herself as part of the group with a life worth living. Had Black Maria fought against Robin before the Enies Lobby arc, her words may have had more of an effect. But Robin knows now that her place is with her friends and that they trust and rely on her. No amount of taunting could ever change that.
