I'm traveling to Brussels in July by myself and found this hotel, which looks nice, located in a decent area, is cheap and has a breakfast:

http://www.solmelia.com/solNew/hotel...digoHotel=6803

Yes, the Melia Ave. Louise is a good location and if the OP can find a room there, she should take it. I've walked past that hotel dozens of times, it seems fine.
BL, the Rue St. Roch and rue Verhas are not areas that particularly appeal to me. The Ave. de la Bugrane area is out by Heysel, which is convenient if you're attending a convention there, but a ways from the city center.
Of the list of BnBs that I noted above, my very first choice would be Ursule La Libellule. Excellent location, close to the Ave. Louise and to the Chaussee de Waterloo/Chatelain area, which is a good residential area. I would pick that one over all the others. But from the rest, La Casita, Zinneke, La Conciergerie, Casa Belgo Argentina and Chaussee St. Pierre look to be in ok locations.

I will be by Ursule La Libellule this afternoon, will give it a look.

Well, I went by. Still think it's the best choice. The BnB is located in a medium sized apartment building, I'm fairly certain it has an elevator. The view from the apartment to the street isn't particularly attractive, but
it's right next door to a good Italian restaurant, Dolce Campagna. The building is about 1.5 blocks from the Ave. Louise and there is a tram stop (trams 93/94) right at the intersection of Vleurgat and Louise. Go up Vleurgat a block and you come to the Jean-Claude Biguine flagship salon in Brussels and right next to that is the Parc Tenbosch. There are many very good, moderately priced, nontouristy restaurants within an easy walk of the BnB (Parachute Parc, Le Fruit Defendu, Lettre a Elise, Toucan, En Face de Parachute, La Poste, etc.). You're also an easy walk from the terrific Wed. afternoon street market on Place Chatelain and the Horta museum.