I have several friends and family that take that much and that much is on my medication list for every doctor I go to and they ( even the ID doctor) said everything I am taking was fine. It is a good Covid prevention also and I have never had covid either and I was never over cautious about being anywhere because of Covid.
So I keep taking it.

The recommended daily allowance is 1000mg, with more for specific needs (such as a deficit.)
Here is an answer about safety for you from the Mayo Clinic:
https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/expert-answers/vitamin-d-toxicity/faq-20058
Here is a caution - Vitamin D is a fat-soluble substance, which means your body has no way to eliminate it, and it can be stored in your liver and fat tissues. Too much over a long period of time can become toxic, affecting your body's ability to absorb the calcium needed for bones and teeth.
Also, the Ivermectin she lists is a prescription drug in the US approved to treat parasites. Off-label use is controversial.

Sue