Thank you so much for this advice. I will try everything today. I do tend to talk to her and pet her whilst we are walking and I also give her treats when she does something right but will not be doing this anymore. Cheers.
While I agree with the general sentiment talking/petting/treats do have their place. Especially talking.
It may help to have verbal commands (walk on, whoa, easy, "eh!", enough! etc). Some horses respond VERY well to vocal cues (the intention even if they don't know the meaning though you can teach meanings). What you shouldn't do "oh what a good girl, you're so pretty, so we're just walking down the road now, oh the sun is so nice, now don't be worried that's just a little puddle" (stop and pet, treat after crossing puddle etc).
Just expect her to be good and you need to have authority. Don't ramble, don't think talking/pets/treats are "bad" though, they just need to be done appropriately, and as I said appropriate talking may be very beneficial to you.
If she is fresh give the lead a tug, but sounds like she is relatively quiet on the ground?
Out of curiosity when was she weaned? Work should always be age appropriate but no reason she shouldn't be 110% behaved on the ground at this point. At this age she can begin doing more physical things like lunging (do take it easy and do NOT do these things until everything else is solid) which I would do before working on saddle stuff.