Numbers would help.

How narrow is narrow, in inches? What's your budget? How much storage?

The distance from the wall (that the sink goes on) to the tub is 42". I tried an 18" vainity and it took up almost half of the space! So I think something around 12" deep would be better. As for storage, I think something as large as 36" would fit, but it of course doesn't have to be exactly 36". The sink would ideally be on the right side of the vanity. Here is a pic of the wall where the sink goes. The measurement from the left side of the mirror to the cabinet is 34.5”. From the right side of the mirror to the wall is 20”, and the mirror itself is 16”

I'm still not clear with your numbers or your photo. So the vanity you're looking for would be 12" deep max and 36" wide max?

What are the maximum dimensions, width and depth, for the vanity you need?

I think ikea might have one in that depth.

Hope this helps you guys! Thank you for helping me!!