Thanks for all the great information up front. It helps me formulate a response.
Many dogs dislike the lead. Some may only associate the lead with unpleasant experiences like going to the vet. I have a method of leash training that has worked for exactly the problem you are having with your dog. I've used it with excellent results for over 15 years. It has worked for young puppies and juvenille dogs and even adult and older dogs. I've even had dogs that used to spin on the lead walking next to their owners in an hour. Of course it usually takes multiple sessions and lots of training to achieve lasting behavioral change.
Dogs can be so stubborn. Don't feel bad most will do pull and bite at the lead if given the chance. If your dog is pulling while walking then a little retraining is in order. It's a matter of getting your dog to want to come with you regardless of the leash being attached. You will get multiple answers depending on whom you talk to as opinions differ on the best method to solve this problem. Some experts will suggest a Halti (head collar) which you can try. I personally believe in establishing control over the dog with training. I use a chain collar for training purposes. For strong stubborn dogs, some trainers recommend a prong collar. They are effective as a training tool in the right hands. I do not recommend them for owners as there is too much chance of them being used incorrectly. They do now have a harness with a leash clip on the chest. This will pull the dog's front end around to face you if they pull too much. It is a great training tool as well.
To begin with, you will need to walk her by herself so she learns without the distraction of your other dog. Number one, put your dog on a leash before leaving the house. Make your dog sit or lie down before leaving. You walk out first and the dog should follow you out. With a proper walk, the dog should be right at your side or slightly behind. You dog should be paying attention to you, frequently glancing at you to be sure you haven't changed your mind about where you are going. I will be using the word correction. A correction will indicate a short quick tug and release of the leash and you can add a firm low toned verbal reprimand of NO since most dog's know the meaning of no. It is meant to remind the dog that she is supposed to be paying attention to you. Initially, keep training sessions short and where there will be minimal distractions even if it is just in your yard. A walk should be fast paced and not a stop and start exercise. The dog should not be investigating, sniffing or socializing on the walk. Walk to a destination and allow the dog some time at the destination to do those things.
I use a food and praise reward system. I use almost paper thin pieces of hot dog as the oil from them coats your hand and keeps the smell on your hand. They may be called vienna sausages in your country but they are not hot or spicey. Let the dog smell the treat in your closed hand. This gives your dog motivation to be by your side. she should be happy to follow your hand around the yard. Keep your leash short, but without pressure on it. If the dog starts moving away, a correction toward you should be made. Give her a treat every once in a while initially so she understands walking by your side get her treats. Try to time it so it is before she gets distracted. If she starts to glance elsewhere, give a correction and tempt her with sight of the treat. When she is back to paying attention, reward her with the treat in a low calm "good girl". No excitement to your voice as you want her calm. Repeat when you think hers attention is shifting. As she gets better at paying attention to you and your "smelly hand", make corrections giving more praise and less treats. Before you know it, your dog will be walking right next to you all the time, with or without treats. When you stop, praise your dog with your voice or a few pats to let your dog know how good she has done. You can train her to sit or lay down when you stop if you want as well. This helps prevent hers trying to run off if you stop to talk to someone.
Once your dog is pretty much always walking at your side, you will want to make a correction any time she stops paying attention to you. For instance, they are looking at a cat in a yard, give a correction so they look at you. if she is busy looking ahead and hasn't glanced at you for awhile, give a correction and reverse your direction. Do not stop and wait for the dog, just a quick correction and reverse and walk. They learn to keep an eye on you as well as on what else is going on. Try an be confident during these training sessions. Try not to look down at your dog but more out of the corner of your eye. Act like you are paying attention to the scenery. It sounds strange, but it does work.
Once your dog is doing well in the yard, try adding a few distractions such as family in the yard, then progress to another dog around continuing to correct if she even looks like she is going to glance at the other dog. If you wait till she is already distracted, it is too late. You have to catch her before she focuses on the other animal or person. It is a lot of work and takes lots of practice but it does work. Once she is doing better on the leash you can add your other dog into the mix but will likely have to do a little retraining with her as dogs get a pack mentality when with other dogs and will revert to the previous behavior. However, the retraining with the other dog present goes very quickly.
This method should take care of your problem. You can also use a dap collar. They are usually used for anxiety but may help for this situation. They use pheromones to calm a dog. They are usually found at pet stores and vet offices.
Medications from your vet may be appropriate for the beginning of your training session but I prefer not using medications as the dog has to learn to behave without the medication. It is helpful to have a calmer dog though when starting out.
Some owners will go into their garden and tire their dog out a bit by tossing a ball or frisbee or even a stick to help tire them out before taking them for a walk.
I hope this information is helpful to you. If you would like any additional information or have more questions please don’t hesitate to press the reply to expert or continue conversation button so I can address any issues you still have . If you do find this helpful, please take this opportunity to rate my answer positively so I am compensated for my time.