In reply to crossdressingrodney:
I'm pretty sure Nature go on quality of the work not the pictures you submit. Having said that I missed out on the front cover of journal of the american chemical society because I was on holiday and couldn't send them a nice looking picture for it.
Depends on who she's consulting for. If it's a university then you should be able to get a sort of technician/demonstrator rate - basically what you'd pay a PhD student to do some teaching. 10 years ago I would have thought £25/hour seems fine, so perhaps £35.
If it's for commercial then much more. They're avoiding a lot of costs to acquire the skill, you'd probably be better charging a fixed cost for a given job. I'd say £200/hour worked - but really that would exclude any buggering around - so if it takes 4 hours of sitting in front of an image processing package and then just 1 hour of extracting and analysing data you'd only get 1 hour as the program could run while you worked for other clients.