I am sorry to hear that your older female ***** ***** has been urinating in the house. I would not consider this a normal old age thing, but older dogs tend to have health issues that can lead to breaks in house training manners.
Is she eating and drinking normally?
Is she able to get around comfortably?
Any difficulty when she is urinating or defecating (straining, having trouble getting into position)?
Any change in appetite?
I do believe that a thorough physical examination and a geriatric blood profile may be helpful in figuring out why she is behaving the way she is. Many laboratories offer a mini panel that hit the highlights and allow you to see if her organs are functioning normally for a reasonable price.
As some dogs as they age their organ systems don't work as well as they once did, and waste products that their organs usually filter out build up in the blood stream and that affects brain function. They may behave much differently because their brain function isn't normal.
Of course if she is painful then getting into position to pass urine or stool may be hard, so she doesn't fully eliminate which can lead to accidents later.
If her physical examination, urine, and blood tests look relatively normal for a girl her age then this may be more of a cognitive age related problem. At her age this may be related to "sundowner's syndrome" or beginning senility. Their symptoms often tend to occur more at night when they are sleepy and more easily confused. It's dark and if they awake they may not remember where they are or what they are supposed to do. As dogs age, just like people, they tend not to sleep as soundly and as such may wake multiple times a night.
In some cases they are over-tired and cannot fall asleep. It is common for these pups to pace and they may sometimes vocalize or stumble too in their confusion. They can even forget their housebreaking habits as things progress and eliminate in the house.
If this sounds like her I recommend leaving a night light on at night to help her orient herself. I'm sure it will help to speak calmly to her as well and resettle her.
Sometimes changing the diet to one high in antioxidants and brain supportive nutrients helps. B/d diet by Hills Prescription Science diet products is an excellent one.
A medication called Anipryl (l-selegilene) can also be very helpful. It increases brain neurotransmitter chemicals.
If she is having trouble sleeping you can also try a supplement called Melatonin. This is a naturally found hormone in dogs and people that helps regulate the sleep/wake cycle and is involved in seasonal shedding in dogs.
This is a medication that we do use sometimes in dogs to help them relax and sleep, and in cases that have abnormal shedding patterns related to seasonal light changes or abnormal growth hormone fluctuations. The usual dose in dogs is 2mg to 12mg per dog every 12 to 24 hours. Make sure to give a dose 2 hours before bedtime.
Make sure to read the label and DO NOT use the fast dissolve tablets of Melatonin with xylitol as xylitol is toxic for dogs.
To help calm her I like DAP (dog appeasing pheromone) diffusers or collars very much. This is a synthetic analog of a calming pheromone a nursing bitch produces when nursing. These can be used along with a homeopathic, such as Bach's rescue remedy. This is a calming drop which can be added to food or water.
If none of this seems to be working antihistamines often have the side effect of making a dog sleepy. If she does not have any history of glaucoma or heart disease you can give her Benadryl (diphenhydramine only don't use the combination products with decongestants or acetaminophen as they can be toxic for dogs) at a dose of 1mg to 2mg per pound of body weight or one 25mg capsule per 15 to 25 pounds of body weight orally every 8 hours.
But I think I would start with an exam and some testing to make sure there isn't a disease process causing her symptoms that we can help her with before assuming this is related to old age cognitive issues.
Please let me know if you have any further questions.