1. Frame her in an artistic way. Go by the rule of fours, as in her head should definitely be cut off, but the empty plate in front of her included. It's art, don't ask questions.
2. Don't tell her when you're about to take the photo. It's statistically confirmed that candid shots are much more beautiful.
3. Make sure to capture every awkward face she makes. Because she is bound to make a lot considering you're taking photos in a restaurant, so it's prime opportunity. Snap away!
4. And finally, don't encourage her to wear makeup when she goes out to dinner. She'll definitely appreciate looking exhausted in every picture.
And, that's a wrap!