Bent Dog Tail Normal?

A quick look at the avatar suggests nothing was wrong when that pic was taken

 

Harri has a kink in his tail - it will straighten if I hold it in the correct position but he'll never do it by himself. Naturally it curls over and leans 15degrees from the vertical.

If your dog has always had a bent tail I'd ignore it but if it's a new thing then get it checked

 

To me it looks like that now your little one is grown older, so does her tail grow and it has got heavier. As it is not docked..yes it will become 'bent'/curved. It you dog is not in any pain and is able to move it about in comfort, I would say it is a case of natural development.
My terrier girl had floppy ears to start with but now one of them won't flop anymore and it sticks straight up in the air...all the time ...and yes, she too have 'wonky' tail. They are not designed to hang down straight like with some other breeds..nor they are super curly neither...just perfectly wonky!

 

I know the feeling