I'm single, 80 and looking for a place in Nice for an August stay.
We stayed at Hotel Solara . It is a budget type hotel , but we really liked it. Clean, good air conditioning, close to everything.
Read reviews on tripadvisor , they basically same all same thing. Well located hotel with truly kind and helpful staff.
I second the Hotel Solara. I stayed there as a senior solo traveler in July 2012 and I was very happy with the hotel, especially considering the budget friendly price. It's not on the Promenade but just a couple of blocks away on a pedestrian only street just down from Place Massena and a tram stop, a very convenient location.
Consider Hotel Le Royal on Promenade des Anglais.
Thanks to you women who have "been there, done that" K