I can only attest to the way I do it, if she gave you the original bottle it wasn't diluted.
We dilute small amounts for the monthly, but the daily is much more.
It sounds like you are on the right start, but the Ivermectin is not diluted.
If you are still worried, call your vet office and double check, but legally if we dilute out a drug it wouldnt go back in the original container, nor would it be sold with no label saying it was diluted, and again, for demodex we don't dilute it.
Hope this helps,
Dr.V
Dr. D.A. Vamvakias
Veterinarian