I think the word stubborn is misleading. It means to stick to a single viewpoint when there is overwhelming reason not to - though we often use it as shorthand for 'just not wanting to' which is not quite the same thing.
If a dog is presented with a good reason to change their viewpoint, they will. They have no ego to attach themselves to the old viewpoint against all reason. Now, among individual dogs, what qualifies as a good enough reason may vary so that some dogs seem much easier to convince than others.
So if your dog doesn't want to do something, you've not found a good enough reason for them to that overwhelms their reason not to.
As the OP says, being able to catch up a person they like that's ahead of them = a good enough reason.
Being nagged (or whatever you're doing) by the person holding the lead = not good enough.
As pp have suggested, I'd be looking at what factors sit on either side of that equation and trying to change them so that my 'argument' for walking with me on a lead is far more convincing, to the dog.
- What might be putting the dog off walking on lead with me
- What can I use to make walking with me a more enticing prospect
And yes: a vet check for pain or discomfort as well as an approaisal of the equipment to make sure it's not causing any = always the first step.
(The point of debating the term stubbon is because, while you continue to think of her as stubborn, you may risk missing all the real reasons she has for not wanting to walk. Like 'guilty' or 'naughty' they are terms that essentially blind us to looking for root causes.)