Value for 2007 Mazda 3 with 46k miles

Here the scoop:

My fathers 90+ yo neighbor has failing health, but wants to stay home as along as possible before moving to hospice, but needs more help from CNAs to stay at home. In order help her pay to do this, my father  is helping helping her sell her car. He's not sure what to ask, and FB MP is no help.

Here's the details I have right now:

2007 Mazda 3, 46k miles, auto, mechanically sound, minor door dings but otherwise good condition. Truly used by little old lady to go to store, medical appointments, and church. Located in Bradenton/Sarasota area of FL.

Anybody have any suggestions on where they should start for asking price? 

Looking to move it quickly, so I suggested Carmax To get an offer in hand and then work from there to figure out what to ask.

Maybe Mazda3s aren't popular where you are but Corollas are.  I would head out to FB marketplace and see what people are asking for a '07 Corolla w/ 46k miles

'07 w/95k asking $7k

'07 w/ 79k asking $8k

Both of those Corollas are low option models and both are old ads (slow selling.)  

For a quick sale, I would come out at $6,500.  Try to hold your price the first weekend.  If it is as nice as you imply, it will be gone the first weekend.  If not, certainly sold by the following weekend and even more so if your willing to accept $6k.  

I then went looking for ANY CAR that was '06-'08 w/ under 75k and I focused on cars that would be its contemporary (not a collectable or lux car.)

'06 Camry @ $9k

'08 Civic @ $8k

In reply to John Welsh :

Thank you, I hadn't thought to cross shop similar class cars, but it makes a lot of sense once you suggested it. 

What I discovered from my quick shopping is just because you want to buy a car w/ less than 75k miles, doesn't mean you will find one with less than 75k miles!  So, if you are a traditional buyer who thinks low miles equals reliability or value than you'll need to be open to more than just one model.  If you are that buyer, you'll also need to act quickly if you genuinely find one.  

Of the 4 I listed, only the Civic looks to be a genuine "well kept" condition.  The others have the signs of cheap attempts to tart them up like aftermarket wheel cover on the Corolla or mismatched wheel covers on the Camry (different styles on each side.)  

The car you have sounds like an ideal car for a young driver.  

In reply to John Welsh :

I agree, it's a southern car with low miles, but had been driven regularly so things were kept moving. 

If I could justify buying and holding it for 2 years, it would be perfect for my 14-1/2 yo back here in Mass.

But I'm cheap, and I want to see them get the most out of it to help his neighbor, so I'm not the right buyer.