Welcome!
I would agree that testing is highly contingent on your needs. If it will allow her greater access to services or opportunities that might be important to her or your family, then it can be very helpful. Or if you are questioning a 2e (gifted/learning disabled) situation. Otherwise, especially in a homeschooling setting, it's just icing.
FWIW, I conduct assessments of this kind professionally, yet have not had any of our children assessed. We haven't needed it so far.
If you do decide you want testing just for your own interest and guidance, (i.e., not because of some specific, urgent need) scores are usually more stable after about age 8 or 9.
