Out of her peers, does Kelly seem to have some of the most consistent first week sales for her albums?

This is of course taking into account the decline of record sales and the amount of promo. (Taking into account the industry climate, her first week sales in 2015 are comparable to her first week sales in 2004 IMO). The differences from album to album when you take that into account don't seem very big. She hasn't really had an album that got more promo than another but didn't sell as much, had less promo than another but sold more, etc. They seem very consistent, especially given the fact that they've all debuted in the Top 3.

Thankful (2003) - #1, 297,000
Breakaway (2004) - #3, 250,000
My December (2007) - #2, 291,000
All I Ever Wanted (2009) - #1, 255,000
Stronger (2011) - #2, 163,000
Piece By Piece (2015) - #1, 97,000

Other albums that weren't included:
Greatest Hits: Chapter One (2012) - #11, 75,000
Wrapped In Red (2013) - #3, 73,000

except for that huge decline

Let me convert these all to 1999 sales so that the record sales decline can be accounted for:

297,000 x 1.27 = 377,190
250,000 x 1.48 = 370,000
291,000 x 1.86 = 541,260
255,000 x 2.57 = 655,350
162,000 x 2.90 = 469,800
81,000 x 4* = 324,000

75,000 x 3 = 225,000
73,000 x 3.24 = 236,520

Granted this is using WW trends for US numbers, it looks like the answer is yes, especially considering the lack of promo for PXP.

I got the yearly calcs here
http://atrl.net/forums/showthread.php?t=780998

Someone clearly can't read.

The receipts

And just for some further info, here are the singles each album was led with...

-Thankful - Miss Independent, Top 10 on the Hot 100 and #1 on Pop radio. Hit single.
-Breakaway - Breakaway, Top 10 on the Hot 100, ended up being a big hit due to its longevity but hadn't really smashed THAT hard before the album came out.
-My December - Never Again, Top 10 on the Hot 100, decent sized hit that didn't have a ton of longevity due to the record label ending the era early. Also, the massive success of Breakaway was a nice lead in.
-All I Ever Wanted - My Life Would Suck Without You, #1 on the Hot 100, record breaking hit single.
-Stronger - Mr. Know It All, Top 10 on the Hot 100 but similar to Breakaway in the sense that it was very slow moving and didn't reach the Top 10 until album release week.
-Piece By Piece - Heartbeat Song, very very slow moving single that has so far peaked right outside the Top 20 but still moving.

She seem pretty consistent, I hope PBP will sell more in the long run, like all her albums.

Reading is fundamental, sis.