I usually comment on cat behaviour, but have owned dogs in the past, and I know that yelling or punishing a shy, nervous dog will not, repeat NOT, do any good but just reinforce or make worse her nervous state, nor will it stop her peeing inside. I suggest that since she was rescued from a puppy mill, that she
never received any kind of toilet training at all, she just went when and where she could, so she's never learned that it's inappropriate to elminate in the house. I'm sure you'll get some expert advice from people on how to correct her peeing inside (if it's even possible at this late stage in her life).
However, "due to the whole family working long hours" it seems impossible to take her outside at regular intervals (say after meals, or every couple of hours) to pee outside. Hopefully someone will have other suggestions.
Good luck! I think you're going to need it.
