I agree with Klara, theKlara. The strategy I often use is to devise a character that has both a superpower AND a significant weakness, and devise a plot in which her superpower is of very limited help, and the only way she can truly prevail is to overcome her weakness.
She may be able to fly, but she is not a detective. Superman can keep law and order among normal humans, but his arch villains tend to be aliens even stronger than him, or like Brainiac, way smarter than him. Spiderman (in the comics) loses half his battles, the designers of Spiderman did that intentionally so the outcome of any given arc would have suspense.
In order for your superhero to not be boring, she needs setbacks to overcome, she has to fail. Fulfill your wish of making her the best in the world at something, or having a unique power. Do not fulfill your wish of making that solve everything. In the story, it shouldn't solve most of the challenges she faces. It's fine if it plays a role in the finale, if flying is, at last, critical to her victory, but it should be impossible for her to achieve victory without overcoming some deficit or weakness she has that truly seems to the reader to give the villain the upper hand.