It is often difficult to calculate the true "scale" of any doll. Most toy companies cheat the true scale and use what the industry calls doll scale. If the doll is an adult size, like Barbie or Tyler Wentworth, it is much easier to establish true scale because the real world is based on adult sizes.
When the doll is a child, like Sasha, then finding true scale becomes much more difficult because the child basically lives in an adult size world. So, a Sasha doll has two different scales available -- child size and adult size. Furniture and accessories can come from both worlds. Remember that adult world scale is based on a male figure 6 feet tall. A female would be based on a figure 5 feet 6 inches tall.
Here are two images to help see the two scales or relationships. First we see a doll family created by Helen Kish who sculpts realistic dolls very close to normal human proportions. The adult doll is 28 inches tall and her brunette daughter is 16 inches tall -- about half the size of the adult. The second image is by Tom Tierney who creates many historical family paperdoll books for Dover. Once again we see the child is about half the height of an adult male.
So this means that Sasha probably lives in a world of 28 inch female adults. If you can determine what the size (scale) of furniture and accessories is, then you can determine if it is in scale for a Sasha.
A good example of real scale vs doll scale is the American Girl doll line. Mattel has used doll scale for most of the furniture and accessories. That means it is under scale for the 18 inch American Girl doll but very close to being real scale for a 16 inch Sasha doll.
If you enjoy creating environments for your Sashas then I suggest that you start clipping photographs that show adult figures in a setting. Then you can imagine how your Sasha would fit into the scene - the Sasha will be about half the height of the adult.
To be continued...