InDesign is VERY similar to that of MS Publisher - very simple to use with tons more options obviously. I designed and assembled our company brochure on it - the toughest part was deciding which type of PDF to export it to b/c there are several options and unless you are familiar with each, you have to research each one.
She'll be just fine. Check into Lynda's tutorials on *cough* some torrent site. I was already very familiar with PS so ID was quite easy to transition to. Good luck