From a professional pov... as the person who ends up sorting such disasters out.. argh.
With my emotional 15 year old with mental health issues head on... oh gawd.
Could you love this dog - yes, he/she is not the dogs you grew up with, dogs are individuals.
Certain breeds I find absolutely pong, my hound HONKS and frankly he loves honking and likes to build up a heady stench. I love him, thus, I tolerate his stench.
I used to be 100% anti dribble, not all dogs do, I never had one that did until him... again, I adore him, thus his dribble rarely freaks me out (and he can hit the ceiling with it!).
There is some wild bullshit being discussed in this thread - collies are rarely HUGE, not all collies are working collies and many are xbred with other things. Working types that end up in rescue and rehomed to the general public tend to be crap at working, hence being where they are. The ones that are great workers get rehomed to working homes, mostly.
If that isn't the case - whilst working dogs DO need lots of exercise and training, that isn't the hard part. The hard part is that most of them are not well equipped to cope with the busy constant to and fro of pet dog life. Being a PET dog is in many respects a MUCH harder job than sleeping in a kennel for 14 hours, going out and rounding up some sheep for 6 hours then back to doze in your kennel/chew a bone/sleep/etc.
So providing chill out time, quiet, stress free periods, avoiding too much busy busy, teaching your dog to relax - those things are important to do and will do a working bred dog FAR more good than trying to exercise his legs off! (All that will do is create an ever fitter dog who can withstand even more exercise!)
Couple of books you should get:
Easy Peasy Puppy Squeezy by Steve Mann
Dog Behaviour and Training Solutions by Sally Bradbury, Emma Judson, Jo Maisey et. al. (produced by the admins of the Dog Training Advice and Support Group from fb) (both available on amazon and as kindle options).
Those will give you some common sense approaches, (ignore that its not a puppy, approach things as if this is a puppy), and a whole TON of info to dip in and out of as and when needed and some useful stuff to read BEFORE you pick up new dog.
Prepare for this to take a year. At least. To get from rescue dog to easy going family pet.
New dogs unpack baggage slowly, as they get more secure, new stuff pops up... you think they've got it, they settle in more.. new stuff pops up.
You need to impress upon your DD that the new dog needs stability, security, a predictable and stable home. That means her, SHE must be stable, secure, dependable etc. He will rely on her - she cannot flake out.
Good luck OP. You're going to need it, this is do-able if you want to do it. I wouldn't advise it... but if you're doing it anyway, good luck!