@Luke Bricca  I am or was a GC and can see about 20k coming into a simple remodeling project.

No formula can be accurate across the board because even “cookie cutter” properties next store to each other differ as to view, location to the street, topography of the land, lot size, physical condition of the property, past remodeling, quality of the mechanical systems, sunlight, utility bills, past use, etc.  

So, I tried to help the situation by getting a contractor to go replace the floor and remodel the bathroom so that the house is nicer for her.

I'm sure your parents know what houses go for around them, is 413k for a new or freshly remodeled attainable there?

Because of this, unsophisticated appraisers reduce as-is value more than they should.2nd, the appraiser estimates the increase of value, based on your remodel plan.

I remodeled complete rental myself.

We added value by re-doing the whole house, installed vinyl floorings, rebuilt 2 and a half bathrooms, re-painted the whole house, replaced all the hardware in the house, installed new lighting, ceiling fans, re-painted the kitchen, and completely remodeled the upstairs.

I have a general contractor license so I also can repair and remodel properties before they go on the market.

Full interior remodel What was the outcome?

The house was completely remodeled and needed nothing.