Is this normal?

[Sadie's_Mom]

Ok I have a 1year old female YorkiePoo..
She is not spayed ..Now the thing that as me confused is that her
nipples are sticking out more and it sort of looks like she's got little lumps like she was starting to get milk.. Is this normal ? She's never been in heat or if she as I never noticed ..no blood or nothing.. Could this be a sign that she is starting or what? I'm 100% sure that she as not matted with a dog as we have a fenced in yard and I always go out side with her or if I'm not out with I make sure to keep an eye on her..

Anyone know what it could be as like I said I'm totaly confusedat this point..