I once posted about noise waking us.
It wasn't a residential neighbour, it was a council-run site.
And it happened every two-three weeks when they had a particular delivery.
DS was a young toddler at the time, so once we were awake we were up for the day.
And I had a job that entailed working until midnight and not getting home until about 1am.
We were always woken early on the day I was at work, so if we were up at 6am I knew I wouldn't be sleeping again until the early hours of the following day.
I had also recently been in a serious accident, which if I'm honest I'm still not recovered from now, more than eight years later. I still get pain, and feel easily tired. And when I'm tired the pain is worse.
So being woken at that time, even thought it wasn't daily, was stressful. I knew it was coming and felt on edge waiting for it.
DS was a good sleeper at the time, and so would usually sleep until 7:30-8am if not woken by the noise. Which was so loud that the first time we heard it we thought it was inside the house.
Complaining didn't help. They did admit that they were not supposed to make any noise until after 7am, but as it was only happening once in every fortnight/three weeks they seemed to think it was okay to break that rule as it suited them better to do so.
I did get some good advice on here, but the comments about 6am being normal for some people didn't help, neither did comments about moving house, or getting a different job with different hours. Because 6am wasn't normal for us, nor for our closest neighbours (one retired, one working shifts and so getting in later at night that I did). It wasn't just me complaining to them.
Moving wasn't possible, we'd moved twice in the space of three years and couldn't afford to do it again. A detached house would have made no difference even if we could afford one. We weren't attached to this neighbour, they were across the road (actually two roads and two large grass areas because of the way our street is laid out) but opposite our house.
Neither was finding a different job an option. The one I have had needed to fit in with DH being away and the times my parents could help with childcare, plus after the accident it made applying for new work difficult as I had to explain why I'd had time off and you can see potential employers writing you off as someone who will always be on the sick when you start explaining accident, near death, long term recovery and long lasting injury.
I feel for your neighbour OP. You're not doing anything wrong as such, but the impact on her and her family even once or twice a week could be far greater than you and your DH imagine.
I'd make a change to my routine if I were you, because good relations with the neighbours are important, and if you knowingly keep waking her now, you might find that she reacts by being noisy at a time when you'd like her to be quiet. And if she moves, you might get worse neighbours than her who do something to annoy you.
If you can use the kitchen yourself, or buy a quieter hairdryer, I think you should. Even if the dog can't go in the kitchen, can you? Would that move you away from the joint wall?
I do think you have to do something now you are aware of the problem, especially as you say she's a lovely neighbour and let you know in a very polite way.