Due diligence should be covered by the hiring of professionals. Had she gone into this without a realtor and lawyer, then the emphasis would be entirely on her to thoroughly research and investigate the entire process. It's wise to educate yourself to the point, at least, of understanding what the process involves. But similar to hiring an inspector, if he goes into the attic and I inquire if the insulation is adequate, that doesn't excuse him from not mentioning a gaping hole in the roof.
We enlist these professionals in order to cover the bases that we know we don't know enough about to do it ourselves.