I think it will look fine either way....if it is lower, you have a dedicated/defined area as your makeup vanity. If it is the same height, that space may or may not be used as a vanity and will just become part of the overall sink area. Only you can decide which will work better for you. A counter-height stool COULD look a little strange in your bathroom and is not the norm, but if you like it that's all that matters.

I had the exact same problem. I picked out the vanity I wanted but did not think about the fact that it wasn't made to sit flush against the wall. I spent a month looking for something else, but in the end we decided to go with something shorter and have it not be against the wall. But we were going from 72" to 60" which is probably not workable in your mom's situation. I did find a lot of vanities that did have flat sides and could work in a corner, if you are willing to have the countertop fabricated. They just need to not have any trim detail on the top or bottom like the one you picked out does. I would just look at the ones without the pre-made tops. Because the pre-made top will still leave you with a slight gap because of the countertop overhang. This is an example: Avanity Modero which is sold everywhere, not just at Lowe's. The cabinet we ended up buying is an Avanity Madison which won't work for you, but I assume it is of similar quality. We are pretty happy with it. The drawers and doors have soft close but I do feel like the glides in my Ikea kitchen drawers are better quality. It is very pretty and I wanted a stained wood so I am really happy with our choice. If I had been willing to go with a painted finish, I think we might have stuck with the 72" Modero.

I agree with Cpartist"s layout and like moving the closet over as suggested by D M so that bedroom 3 has easier access to the bathroom. Do you have room to have the toilet face the tub and add a linen cabinet next to the toilet? How wide is the tub toilet area?

either do a whole wall framed mirror and mirror mount the sconces or get smaller mirrors. pendants in bathrooms are decorative IMO But do say you cant find any over the mirror that you like? there are have to be at least 800 choices, for example the one you like probably comes in a mutli head option. try kichler, hinkely, murray fiess, hudson valley lighting, minka lavery go to their actual websites and look through that way you will not be overwhelmed by say the vast amount on a lighting on line website.