OK! Now that you have a no pull harness, here's what you can do. Keep her on your left side when you walk. She doesn't have to be in heel position, but she does need to stay on the left of you. She can be a few steps ahead as long as she isn't pulling. The reason she needs to stay on one side is that the leash, being hooked in the front, will always be in a position for you to correct her. It's much harder to control her if she wanders back and forth in front of you.
Try to prevent her getting a leg over the leash. That happens occasionally. You can take up the leash slack as needed to help prevent it. If she gets a leg over the leash, it makes it easier for her to pull, so watch for that happening and fix it right then.
Every time she pulls, stop in your tracks. Do not move or speak to her until she turns and comes back to you. Then praise the heck out of her (make the praise worthwhile) and give her a tiny treat so she learns that staying near you is rewarding. Then start walking again. If she pulls, repeat the process. It will take many, many stops and starts before she gets it, but it will happen. Practice this every time you walk, not just when she sees something. At first, it might take 20 minutes to go a relatively short distance, but remember, this is the training phase and you have to stick it out until she learns. The more you work at it, the faster she will learn.
When it looks like she is beginning to get it (after she turns and comes back several times for her reward), you can add a command (like "by me") if she starts to get to far away or puts pressure on the leash. Remember though that this is not formal heeling and in no way should you expect or ask her to stay exactly by your side. You should teach her to heel eventually as it comes in very handy in crowds or tight spaces, etc. but should only be used for a couple of minutes worth of walking. It takes a lot of concentration to heel even for a very short time.
Most of all, pay attention to her while you're walking so you can anticipate any problems. If she looks like she may bolt and run, step to your right. That will unbalance her and make it hard for her to dig in and pull you off your feet.
It may seem awkward at first and you will probably make some mistakes. Don't let that stop you from trying. Just start over from the beginning.
Hope this helps!
PS. I feel sorry for that little pup with the shock collar. I wish the owners would put one around their own necks (not arms) and hand the remote to someone who will randomly zap them without warning or any instruction.