We like small restaurants..no 2-3 star places. Bistros great. Romantic...also nice!
Go to viamichelin.com, select restaurants, select the 7th in Paris, and look at their Bib Gourmand ratings.
There are only about ten 3 star Michelin restaurants in Paris--you don't want any of those because of price.
Bread and Roses, 7 rue de Fleurs, in the 15th, for breakfast or lunch.
Cafe Constant, 129 rue St. Dominique, and Les Cocottes, 135 rue St. Dominique in the 7th. Neither one takes reservations and are popular, so hit it at an off time. Delicious food, friendly staff.
+1 for Les Cocottes, open Sunday, too. We showed up about thirty minutes after they opened and got the last two seats-at the bar. Great traditional dishes, great personal service, a pleasure.
In case you get out of the 7th & 15th:
Le Pantruche
Bistrot Paul Bert
A La Biche au Bois