I used to volunteer at a shelter. Microchips are the size of a grain of rice and inserted with a gun that resembles an ear piercing gun. One would know if they had one. They would be close to the skin and not super comfortable at first.
Providing human microchips are made in a similar fashion when the time comes.
That's what I explained to her. She said "But you can already get chipped in the fleshy meat between your thumb and forefinger"
And I told her "that chips slightly bigger than a grain of rice, and they don't inject it with a syringe. They use a special tool. You'd know." Then I had to explain further that kind of chip was a near field passive RFID (which, thankfully, I didn't have to explain) and that if it was a transmitting chip over radio, it'd have to be much bigger and have an antenna. I was like "your wifi card has an antenna the size of an index finger, and still works like shit" lol
She used to be such a smart lady. I swear, right wing conspiracy websites (like T_D and qanon and shit) have got to be some kind of experiment on how to destroy critical thinking. There was once a time when she would've heard this kind of foolishness and known how dumb it was