I Kept a Low Profile After Arriving in Another World, Until I Didn't

No romance, strong female lead, powerhouse, keeps a low profile. Before transmigrating for the first time, Song Lingzhu was an ordinary wage worker. An accident sent her to a world of immortal cultivation. After clawing her way through countless hardships, she finally became a powerful figure in the immortal realm. Hoping to relax and have a romance, she was instead killed by her best friend and her lover. When she woke up again, she had arrived in a world of magic. What she couldn't accept was that she had transmigrated into the body of an old woman who collected scrap. What made her happy was that the pocket dimension she'd acquired in the world of immortal cultivation had come along with her soul, and it contained all the resources needed for cultivation. To avoid being captured and studied by mages, she keeps a low profile and cleans toilets at a magic academy. She had thought magic was incredibly powerful, but when she saw a mage launch an attack, the mage had to chant first. Song Lingzhu was stunned. In the world of immortal cultivation, she would've died ten or a hundred times over before that chant was finished. She was cautious when she first arrived in this new world, never realizing that she was already a hidden powerhouse.