Welcome to FT!

How the specific airlines she's considering decided to configure their aircraft, the kinds of seats they use, the distance between rows, the number of degrees of recline, etc., make more of a difference than aircraft type. These are all specified by the airline, not the airframe manufactuer. If she's considering Airline A versus B, a post in (say) Airline A's forum asking if anyone there has also flown B and can compare them would tell you what you want to know.

For the future, a more descriptive subject line would be nice - something like "767 vs. A333 - better in coach?" for this thread.