Hi there, you are through to Dr. Jake. Im a UK based vet. im sorry to hear of your concern with your dog, Daisy. urinating in the house could be due to a few reasons, it could be behavioural as you have mentioned, relating to stress and anxiety but it can also be due to medical reasons.
medical reasons for this would include:
a urinary tract infection- this can cause dogs to urinate in the house, they often pass small voids of urine regularly, they can often strain to pass urine and vocalise if this is uncomfortable this is usually due to bacteria in the urine which would require medications from your vets.
female dogs are prone to urinary incontinence where they often leak urine or are unable to hold the bladder as the muscle has become weak, this can occur through the day and night and often results in the dogs having a wet bed in the morning , again there are medications for this to help prevent the bladder leaking
increased urination can be related to an underlying condition with the kidneys - this can be due to degeneration of the kidney tissue where they dont function as well as they used to or other more concerning issues such as cysts or tumours on the kidneys
there are a few conditions which can lead to urination and also increased thirst- kidney issues can do this as mentioned above but some hormone imbalance problems can cause this too , another condition which can cause this is diabetes.
i would recommend making an appointment with your local vet for them to conduct a full clinical exam on Daisy and for them to analyse a urine sample to make sure there is no medical reason for the urinating in the house. they may advise blood tests to check the kidney function, check for hormone imbalances and to rule out diabetes and to do imaging to rule out there is no abnormalities in the urinary system structure
if urinary conditions are ruled out by your vet and its suspected this is a behavioural issue related to stress and anxiety then there is a few things your can try.
using remedies in the house such as pet remedy spray, adaptil plug ins can help with stress related issues.
tablets such as yucalm and zylkene can help with these also which can be purchased online
if these arent helping the next step would be to consult with an animal behaviourist. they will be able to come into your home and assess the situation and help you with Daisys stress and anxiety- if this is stress related, it can take a long time for this to be controlled
i hope all this information helps