@FoxRedPuppy I'm sure a couple of days will be absolutely fine.
@thenewaveragebear1983 I feel for you! They are so fast, aren't they? It could be worms but it's more likely just enthusiasm for all the tastes.
@BleakGarden we started in the garden, just treating when she was on my left. Then I took one step forward and treated if she followed/stayed on my left. I find that if I am consistent with the treats for correct behaviour, she works out that it's all going wrong pretty quickly, and reverts to the last behaviour that got her a treat. Kate Olsen does a great video on this and the key take away for me was that heel walking is a complicated thing, involving many behaviours, and that you can only train one behaviour at a time. So you have to pick one and choose it. So it might be that at first, she gets treats every time she's on your left. No matter what that looks like. Jumping, ahead of you, behind you, whatever (but never let her pull you. If the lead goes tight, you need to stop until it isn't). Then once she's consistently on your left, you change what she gets treats for. It might be 'all 4 paws on the ground'. At first, she'll be thinking 'I'm on your left, dammit, give me the treat!' but she'll soon catch on that the treat comes when her feet are on the floor.
Hazel did really well with a loose lead walk into our village today. By that, I mean that she trotted beside me on my left, paying attention to me for treats, but jumping slightly every time I delivered the treat because she is very small and I'm quite tall. She's relatively far away on the lead, though (probably 2ft) so my next step is to change the criteria to only treat when she's closer to my leg. As soon as the treats are finished it all goes to pot, though.