OP.. It makes tough reading, I'm sure, but you are partly responsible for your daughter's attitude towards Coco... You make too many excuses for her and enable her behaviour towards him.
Love is not just paying pet insurance, paying a dog walker, covering food costs... Love is an action. It's spending time with the dog, interacting with the dog, walking the dog, cleaning his mess up etc.
You say she does 12 hour days but six days a week she still manages to spend every evening at her boyfriend's? Why can't she go to his less often and spend time with her dog? Or, take the dog to his after work so she can spend time with him and give him a decent walk and fuss?
She sounds very, very immature! She wants her cake and eat it too, no matter the cost to the dog and to your health and sanity.
It's time to take the 'mug' sticker off your forehead and tell her that the dog, in order to be fair to both him and you, gets re-homed or she steps up! Stepping up could mean giving up her 6-8 am cleaning role and giving Coco a decent walk, paying for an hour long afternoon walk daily and collecting him in the evening and taking him to her boyfriend's with her....or staying home!
Personally, I think you are going to be fighting a constant battle... You should show her this thread, explain to her that she will do right by you and the dog and re-home him if she has any respect for you and truly loves him. Being cooped up in a flat, even with two short walks a day, is no life for this breed!
Next time...she should get a goldfish!