Kesha

Queen Carly, her ICONIC Tug of War era

Katy Rihanna

Nicki didn't peak with Pink Friday, Starships alone was enough to obliterate the success of that era, even with Super Bass.

So your saying Carly peaked with Tug Of War (2008). That was her debut album.

Her singles "Tug Of War" and "Bucket" did go Gold but I think Kiss was more of a peak...

Kesha, xtina, avril

I think they stan for her "Tug Of War" album.

Gaga.

Kesha.

TF and TFM are two different eras

Lady Gaga
Ke$ha
Avril Lavigne
etc.

Seems like peaking with your first era is a sign of... well...

One Direction. And with their first single, too.

Avril Lavigne

Britney

Christina (Stripped was huge though, and Beautiful is inarguably more iconic than anything from 1st era)
Gaga (The Fame is included on TFM Deluxe for God's sake)
Avril
Ke$ha (but she is really relevant right now, and has had many multi platinum hits & her biggest tour since)

Gaga's debut was TF.. she saw success after that

Those saying Britney are false. Just because the album sold more doesn't mean she peaked then. She was clearly a bigger and more powerful star in the early 2000s (music-wise), mid 2000s (media-wise) and late 2000s/even early 2010s (music-wise again).

Lady Gaga tbh and Carrie Underwood