I love houzz.com 3 lights [traditional bathroom design[(https://www.houzz.com/photos/traditional-bathroom-ideas-phbr1-bp~t_712~s_2107) by grand rapids architect Visbeen Associates, Inc. [tropical bathroom [(https://www.houzz.com/photos/tropical-bathroom-ideas-phbr1-bp~t_712~s_2108) [I put in search box there after selecting Bathrooms the words double sink vanity mirror [(https://www.houzz.com/photos/tropical-bathroom-ideas-phbr1-bp~t_712~s_2108)[[(https://www.houzz.com/photos/tropical-bathroom-ideas-phbr1-bp~t_712~s_2108) [I have the 3 light set up over my single sink and it's only been one year since I renovated. Scrolling through Houzz I see the design trend is now sconces, some mirror mounted, or recessed lights above mirror. I only found these 2 photos above showing something with the light bar over the mirror.[(https://www.houzz.com/photos/tropical-bathroom-ideas-phbr1-bp~t_712~s_2108)[[(https://www.houzz.com/photos/tropical-bathroom-ideas-phbr1-bp~t_712~s_2108)

We have that also...30" cabs on each end. I don't know what kind of mirrors you're doing over each sink. But if they're coming in from the wall a little...say two inches on each side, that's bringing your mirror width to 26". You may also want the lights to come in a little also. Personally, I'm doing double sconces over our sinks. I like the look this gives better and there's plenty of light with the other lighting in our bathroom. Some images for you to peruse:

I think I would have to see a lighting plan (i.e. placement of the ceiling fixtures, etc.) to really give an opinion if two were too much. But by just looking at your windows, they are wide, almost square shaped. With that width I think the the two pendants would be my preference. The other question is do you need the two lights for more light - versus one. My motto on the kitchen is more light is better, especially if you don't get a lot of natural light (I have north facing windows.) You can always spend a few extra dollars and get dimmers on some of the lights if you think you have too much (but can't do much if you have too little.) Someone once recommend hanging balloons to mock up the lights to see if you liked it in your kitchen, keeping in mind that lights that are opaque will probably be less visually impacting than the balloons. But I found the balloons very helpful in decide size/scale/location. Good luck.

I prefer two mirrors as well because I think it gives a more balanced look and it provides defined spaces, his and hers in our case. Your statement about wanting to make it so that 3 people can use it is what has me curious though, is this a what if type scenario or is a 3rd person actually going to be in there all the time? The reason I ask is because DH and I used to make choices based on the what if's a lot. We'd spend the money or compromise on what we really wanted only to never have those "what if's" materialize. We bought a crew cab truck so if we needed to we could tote people but never once did anyone sit back there. We turned a room (that could have been my craft room) in to a guest room and in 10 years it's only been used a handful of times and an air mattress would have worked just as well. So if you want the big mirror because it will actually be used in the context you're planning for, great...then there's a need and that would be the more functional choice for your situation, but if you're just thinking well maybe 3 people might need it, then don't focus on that and do what is more practical for your every day living. KWIM? (And Ida is right, about the two lights)