My cousin, in her 70s, has had chronic lymphocytic leukemia for many decades. several months ago she got both pfizer covids vaccines, now they found a blood clot in a vein near her kidney and a large kidney stone. could this be from the vaccine?

Although rare blood clots have been reported from some COVID vaccines, this is very rare. A kidney stone will not occur from vaccination for COVID-19.

Too lengthy a period of time to have the blood clot related to the vaccination. And the usual vaccine to cause clots is the J&J variety. Sounds like a focal kidney issue unrelated to COVID-19 or the Pfizer vaccine. Discuss causation with your doctors.