Our 5-month-old black female has a very wavy coat along her spine. I like it, but have some doubts about it, does it detract substantially from her compliance with the breed standard? She is from formidable English lines (her grandmother was top US show Lab in 2006). Will it disappear or at least diminish as she gets older? Is it really a problem if I elect to show her? Thoughts, please.

From the breed standard "a slight wave down the back is permissible"

Many show dogs I have seen have the wave and it doesn't seem to be a big deal at all.

My Virginia had a very pronounced wave down her back at that age, it went away with her puppy coat and she now has a very dense and hard coat, with little wave.

Kiku had a lot of wave as well. She's just now shedding out that outer coat, and it looks much straighter. That said, since her mom has a wave, I suspect there will always be at least a slight wave there.

My girls have wave and it became more pronounced when coat came back in after a litter.

I call them "ripple butt".

Yes per the standard a "slight wave" is permitted however many show breeders prefer a wave down the back myself included. So it's desirable to many. You can see my dog in my signature has a lot of wave to his coat and I strive to breed that in my puppies.