there’s no wine in French hell, just vinegar.
Can she tie the address or a nearby landmark into the name somehow? There’s a restaurant in Charleston, SC, called 86 Magnolia, and a restaurant in Key West called 9-1-5 (they’re at 915 Duval Street.) That will help people remember where it is. Cafe on the Corner, Cafe by the Bank, Cafe under the Elm Tree, etc, can also help.
I also think naming after a plant might be nice, like Plum Tree Cafe or the Gardenia Cafe.
La Reve (The Dream), or for a Seinfeldian twist: Le Cafe Reve (The Dream Cafe).
The Onion Cafe
N’est pas?
I think this post simply demonstrates that you should not take his advice. How many “bubba’s” are there in NorCal that primarily associate “oui” with sex rags? So I vote against “THE " or "’S” unless it’s "The ___'s"& even that’s more a Chicago sense of humor, I think.
To be clearI mean the blank as part of the name.
My suggestion is Madeleine’s. Sounds French, has the personal touch of a female first name, and carries the bonus literary reference to the cake that inspired Proust’s À la recherche du temps perdu. “Memories Are Made at Madeleine’s!”
Casa de Cafe I think it’s Italian for House of Coffee
It is a nice name indeed. That’s why it’s already in use by a chain of bistros/restaurants/cafes similar to the one discussed here.
Not original, but at least (hopefully) not the name of a chain of restaurants. Seen on the street (in France):
Le comptoir - “The Counter”
Chez eux - “Their Place”
Au grain de sel - [at] The Grain of Salt
All of them where local bistros, “the neighborhood pub” as it were - or, in French, “le bistrot du coin”. (There is one in Washington, D.C. already, so I guess that’s out, too).
How about “Château Dave”? (Or Barbie or Fran or Bob or whatever non-Franch name is incongruously-appropriate?)
I like this!
How about Le Snooty or That French Place. Or Ish for It’ is Americanish and Frenchish.
My Aunt Ella and her husband Sam named their cafe Sam 'n Ella’s.
Didn’t really take off.
My friend and I actually discovered the best name for a coffee shop/cafe at while at work yesterday. How convenient! We both decided we would definitely go to “The Dirt Room” for coffee at least once a day. Inspired by Blue October.
Cafe Petite
Gay club/bar in San Francisco.
If you liked the movie how about Ratatouille?
Or maybe a name from a classic French film. Rififi is a nice name for a cafe.
Cafe Oui Oui
There is a dish, a throw back to the San Fran gold rush days, a meal of oysters, eggs and bacon, rich and rare, called “Hangtown Fry”.
Call it, The Hangtown Fry, or the Hangtown fritte? 
How about “Le Bonne Femme” or something similar.
Le Bonne Femme de (town/street/name)
The translation is a little loose, but is along the lines of “the good wife /good cook”, or, more often in French, is something that suggests home cooking along the lines of “Chez Bobo” but a little less pretentious.