We have tried a device that lets off a dog whistle sound when she barks but it does not seem to have had any effect. Next is a collar that sprays water every time she barks .... something must work soon!!!
Before you try these kind of methods, take a look at the pinned thread at the top of the behaviour board on the use of aversives.
They can easily backfire, and leave you with more problems - and I especially wouldn't use them on a pup.
My parent's Border Collie used to bark at other dogs as a pup, and their trainer told them to spray her with water when she barked. This resulted in a seriously dog-aggressive adult dog, behaviour which took them years to get to a managable point.
If there is a regular pattern, you can pre-empt it to stop any reward for her barking.
Set your alarm for 2.45am - get up, let her out and pop her back to bed without a word.
For a short while, I would also suggest getting up at 5.30am - and just have a chilled out half hour, with no fun, no games, no food, no walk... then embark on your 6am walk. You can then gradually put the midway through the night visit back - until eventually she can do without it. And then gradually move your 5.30 back to nearer your normal getting up time. If she wakes at other times, I'm afraid it's a matter of ignoring her at this stage.
We never had a problem with Honey waking though the night, but she was an early riser... I would get up before she started creating, and just dozed on the sofa with her... I got up gradually later, and now she will sleep through till 7.30 quite happily. It was horrid getting up really early, but worth it in the long run!