You, knowing that the "dyed" wood likely would lead to death, decide to grab the mass of stones. You believe the stones can be used for a fence. Sydney catches up to you and says that she'll get the wood, and reassures you that it's safe because she's immune.
When recovering the wood Sydney touches it and absorbs the ink, seemingly a benefit of her immunity.
Shortly after touching the ink, her fuzzy inkling hair morphs into a fuzzy octoling hair, she touches her suckers on her out of curiosity, and moans in pleasure, becoming more comfortable with her new form. Her eyes no longer show a line between them and instead are slightly bigger with points going outwards.
Later that day you head back to the shelter after finishing the fence. Sydney greets you "oh hey you're back". She seems to have tied up her hair. She asks you if you want to have some fun tonight. She says she has a condom and asks you if you want to do it safe.