Link between GCA and myeloproliferative blood disorders?

I've had a pmr diagnosis since 3yrs ago & large vessel GCA diagnosis 2 years ago ( now completely treatment / symptom / disease free for the last year )
My older sister recently has an
Essential thrombocythaemia ( ET) diagnosis.

I've read several medical articles that say Giant cell arteritis is known to be associated with a significantly increased statistical risk and co-occurrence of myeloproliferative neoplasms (MPNs)
Notably Essential Thrombocythemia.

" Studies indicate that a prior diagnosis of GCA is linked to a substantially higher relative risk (estimated around 5.9-fold) of developing myeloproliferative neoplasms such as essential thrombocythaemia. "
"Age-related somatic mutations in blood stem cells-such as JAK2 V617F and TET2 mutations-frequently drive both clonal hematopoiesis and MPNs. These mutations promote systemic inflammation via inflammatory cytokines like IL-1ß and IL-6, which are central to GCA pathogenesis"

My questions are therefore:

Should my sister, and I , be informing our relevant specialists of each other’s diagnoses?

Would stem cell testing for mutations be indicated for our family ?

Has anyone else had a family co occurrence of GCA and a myeloproliferative disease?

Much appreciated if my forum friends, and / or the Mayo clinic , could shed some light on my questions?