to be honest if you just want to show off surely the best thing is to pick the dinner she eats the most of and just do that, if I should ever have the desire too show off Harriet as a realy good eater (and I NEVER would, god job really on the whole she is dreadful!), but I would either do veggie cannolloni or sausage, mash and sweetcorn, but that is because it has the best chance of eating loads of, so just pick Zoe's favourite main meal and do that, at 14 months the boy will be eating the same so don't worry about that.
I do feel the need to point out though that there is really big chance that you are going to go to all this effort to show off and your friend will not notice at all, seriously when I take my toddler round to other people's houses I seldom manage to have a sensible conversation with the friend concerned, rather than rescueing her from getting hold of stuff she shouldn't, ensuring she behaviours etc, I really would never have time to notice how well my friends baby was eating, with a 14 month old you may well find your friend is the same, so whatever you do you may not get the result you want!