That shower curtain is pretty intense. Are you sure you want to keep it? It's just a little "precious" for older girls with that much pink, IMHO. The only color that I think could stand up to it with older girls would be a pretty bright orange, and try for a Morroccan casbah look with even more pattern and color and brass hanging lanterns and screens. Layer a cobalt blue curtain under the pink and use some metallic chains for the tieback for the pink curtain. Paint the ceiling turquoise. You can get some talavera or Turkish tiles on Ebay and frame them for an accent. If you have a drop in sink, you could replace it with a talavera one. They aren't that expensive and give lots of style. Cobalt blue bath accessories and rug with other hints of turquoise and pink here and there and it would be fab. As an alternqative, I could definately see doing a fun apple green and white bathroom, but not with that curtain. For green and white, use the chair rail/wainscoating approach and put the green below with white above. A fresh gingham check or ticking stripe for the shower curtain and add in more color with different shades of green towels. A dark green rug and various green accessories would complete the look.

We have redone 4 bathrooms in 3 houses in the last few years and my advice is to go to a local counter top store and look at more options. We found a local place that makes vanity tops in several more options and higher quality than the box stores and they add the sink you want and drill the holes. It was cheaper and we got a way nicer top. We did one from HD because it’s what the MIL wanted. We found it was way thinner material and was not as nice my hubby and I hated it.

My son has the Archer sink in his bathroom and he really likes it. He likes looks of it and the fact that it drains very well compared to rectangle sinks that are completely flat on the bottom? Not sure of the length of his vanity but it is longer 48 inches by 21" deep. Here's how it look in his bathroom

are you replacing the tub tile at all? or just the scroll piece? another idea is to take the same quartz countertop and have the top portion of your tub surround done in the same. that way both vanities and top of tub all match. doing a solid color would work better here since you'll want to coordinate w/the tile floor. If you did that, take the tile off the wall above the tub and you could do something like this If keeping that tile on the top of tub, then it might be an issue. you may just want to keep the scroll piece under the window. that's up to you. all depends how far you want to go. if you remove the scroll, you could do a little wood shelf across, below the window, for plants or orchids. as for the mirrors w/the lights in them, they're all over. just google 'vanity mirrors w/lights', or vanity mirrors w/medicine cab" . they are a bit pricey though. 600 and up for the very nice ones. Robern medicine cabinets are a well known name. if you want a taller medicine cab on the side, you will have to have the recessed portion of the wall made taller. as for the tiling portion, yes, just the front wall,,,you would paint on the side portion. I really like this look for your room. you don't have to do MOP tile, it was just a suggestion. there are tons of beautiful tiles you could use. If you did more of an ivory or subtle countertop that plays well w/your tile floor, then you could have more options to play w/some tile. The sconces pictured here are also nice, but there are many other types you could use as well. Don't want to bother w/sconces? then ditch your mirror and buy a backlit, or complete edge lit mirror like this one. you could still do your tiling like shown here. These are also very flattering. this countertop is limestone, below, and is more of a neutral, greige color. i would keep your ceiling dark, like you have it,,maybe do the walls a lighter shade...all depends what you pick for the vanity and tile. Having the mirror cut down isn't expensive. hopefully they can get it off the wall w/o breaking it. doing the tile around the mirror defines that area and gives it so much more appeal.