Chances are she'll be making pop classics well into her 30's which start next year, based off the successes of Prism. 40's if she can transition well. We'll have to wait & see.
If the last half of PRISM is any indication of what she's transitioning into, she'll probably have Adult Contemporary appeal along the likes of Colbie Caillait, Jason Mraz, and her boyfriend, so ATRL won't use ha.
She needs to evolve starting right about now. She can't keep singing the same type of stuff about the same type of things, she's pushing 30. She plays up the juvenile aspect of herself, which is fine, but it's all image and hit singles and she needs to demonstrate more depth in her persona. The biggest concern is what kind of show can she put on, how to make her show stand out and how to evolve as a performer. Her major live performances have been super disappointing lately!
All that said, I'm sure she's aware of the need to keep a step ahead in pop. The fact that she enjoys broad success, works hard and continues to be likeable and relatable can help her sustain. But 20 years? She needs more depth.
Mmm she would be flopping hard by now if she was. Stay pressed though
If social media had existed back in the day, Paula Abdul probably could have stretched her career out a few more years as well and still ended up with the same result.