Urine problem?

My first thought would be an infection but if it has been going on for 6 months it is unlikely, possible, but unlikely.

Next option is too much protein in the diet. It could be from their saliva when they clean themselves. A high protein diet can often cause the saliva to change and in turn stain the dogs fur when they lick themselves.

Yet another option is it could be from the urine itself and that it is overly concentrated from the dog not taking in enough fluids.

is there anything i can give her, she drinks a lot so i dont think it is that. They are both on dry food.They have nothing added to the complete food and don't have any tit bits.

My dog is white with short hair and is a little rusty/brown on the back end.. And there is nothing wrong with her

I think its normal for light colored dogs...

What dry food are they currently on? Or more importantly what is the protein content... Have a look on the packaging and it should give you a percentage amount.

Around 24% is good, if it's much higher than that I would consider switching foods. There may be a lower protein version of the same brand you are feeding. High protein foods are mainly marketed at very active dogs and working dogs as they need the extra energy. Smaller breeds or breeds who just go for a daily walk don't need the extra energy.

You can also get products to combat staining. Angel eyes is one but I am personally not a fan, you add it to their food and it helps with staining.
Or you can do what I do and change the diet and use a product on the actual hair such as Eye Envy to get rid of the staining that's already there.

Pop into your local pet store, they will have plenty of stain removing products for dogs, they are usually marketed as tear stain removers (red staining under the eyes).