BrailleNote Plus, iPad and PDF files

Hi all,
I work at a university library and am supporting a student who uses a Braille Note Plus connected to an iPad (she doesn't really use the tablet of the Braille Note preferring to use the iPad). She uses a combination of Braille output on the Braille Note and Voice Over on the iPad. One of my roles is to source the books she needs for her studies, many of these are supplied to us by publishers in PDF format. Also many of her course materials will be provided in PDF format from her lecturers. We are trying to find the best way for her to use PDF files on her set up. I am aware that we can convert the PDF files into other formats (as will be necessary for inaccessible image PDFs) but I am trying to find how she can use accessible PDFs without have the extra step of converting them to other formats first.

We had a go with Adobe Reader but encountered problems, we couldn't work out on the Braille Note how to switch the focus from the Adobe Reader menu to the actual text content of the file. If she disconnected the Braille Note I could get Voice over to read the text of the PDF file (by literally pressing on the screen in the text area of the PDF). Once we connected the Braille Note again it got stuck in the menus again. Has anyone got experience of this? Or perhaps got any suggestions of alternative PDF apps?

thanks in anticipation
Sue