She hulk doesn’t have true weaknesses in terms of any physical problems, but that’s not really a problem for the show she is in.
For example, Rey from Star Wars gets the Mary Sue criticism because she has few real struggles, but is also in a “heroes journey” type story where the struggle and growth of power is a key part of the story.
She Hulk is more a comedy and deals with the instant becoming of a celebrity…in a way the protagonist didn’t want, and the impact that has on her life. So the traditional “hero struggles” aren’t really q part of the story, and so the lack of those qualities doesn’t really affect the story.