Well done you on taking on this girl .
You have two problems here.
Taking the pulling first, that is down to training. There is every chance she hasn't done anything like it before and is overcome with excitement and forgets herself. Your husband can always do lots of changes of direction with her to start to focus her attention on him, and there is also 300 peck (there is plenty on this on the internet if you search for it). They both work but as with any training they need patience; a headcollar may help in the shorter term but it is a training aid and not the long terms answer to the problem. If she is food motivated, reinforce her heavily when she walks beside you. You will probably find that these exercises tire her a lot to start with and that she won't need the five mile walks. Lots of short sessions will get you further faster.
The other problem is separation anxiety, which is hardly surprising given the circumstances. By the sound of it your husband will have to do most of the work as she seems to have attached herself to him. The way to start this is by leaving her alone on the other side of the door with a biscuit for one second and then re-entering the room. At no point should you make a fuss of her; just do it . Do this until you are happy that she is OK left for that duration. You then very gradually increase the time she is left, never leaving her to the point where she gets upset; it this does happen inadvertently go back to leaving her for the duration at which she was comfortable and then extend the time periods again. As the time extends, mix up the duration of your departure, so sometimes it is a minute, sometimes it is a minute, etc. After you can leave her for 10 minutes, use a different room and start all over again from scratch. When you can leave her in a number of rooms, repeat all over again but leaving the house - just for a second or two at first and then for longer and longer. At first you can just stand outside, but then try moving away out of sight, and only when you are sure she is comfortable with that try starting the car (you don't want that sound to be an indicator of abandonment).
Obviously when the periods of time for which she is left you can practise loads of times every day - the more you can do this the better. The goods news is that, generally speaking, once you can leave a dog for half an hour you can safely leave it for longer (although there are exceptions!).
The other thing to do as she progresses is to mix up your cues. Dogs are great readers of human body language and they very quickly learn patterns, so she will notice that you put your shoes/coat/hat on before you go out and that you pick up your bag and the car keys. By mixing up the cues you can teach her that there is no pattern, so put on your coat and go and watch the television, or take your car keys with you when you make yourself a coffee, etc. It will all help in the end.
You will find that some of the behaviours you see now will moderate or disappear as she becomes more confident and secure in your household, but the separation anxiety is one to watch and deal with now as you will save yourselves some headaches in the future.
Good luck and let us know how you get on.