I completely understand your concern OP.
Unfortunately in my experience (my own and other people with adhd) med titration does seem to be an art not a science and very much is a case of trail an error to work out the best for an individual. Then once you've decided which one to go with, you need to work out the correct dose, and which formulation in terms of release profile. This does not appear to correlate to anything tangible like gender, size, weight, age etc..
So it can be a drawn out and expensive process. In addition whilst undergoing private titration it is likely she will have to pay for the meds too- some of which are horrifically expensive.
Headaches are a listed side effect but I haven't found it an issue and I haven't heard of it being one for others. I do think though, that the meds often reduce appetite (until they wear off), and sleep (again only until they wear off), and many of us aren't great at remembering to stay hydrated. So it can be these things, that contribute to a headache when adjusting to meds.
One thing to bear in mind is that in general once a stimulant med has kicked in (which is same day, within a relatively short time frame) you straight away have an idea of whether it is having a beneficial effect. That's not the case with non stimulants which only take effect after weeks or months- in that sense working out of a particular med has potential to help is often easier with stimulants.
Similarly stimulant med effects wear off within a short time frame (depending on their release profile). So in general most of us on stimulants go to bed without being medicated and any issues would therefore wear off).
Many of the issues you mention are symptomatic of adhd, rather than a choice or something she is able to change in the way a neurotypical person might expect.
Hope that helps a bit.