Have they tested the tumors for mutations/HRD, or did they just do a germline test on her blood? If they think it might be endometrial in origin, the tumor should have at least been tested for MMR deficiency (by testing MLH1, PMS2, MSH2, and MSH6) and for p53. I don't know offhand what the routine genetic tests for ovarian tumors are.

If the tumor is not MMR deficient (above genes, except p53, all normal by imunohistochemistry-IHC), you should lobby for testing the tumor for mutations in the POLE gene, if they haven't already, either as part of a large sequencing panel, or as a single gene test. (I ended up paying $450 for a single gene test from Stanford out of my pocket two years ago.) You really need to watch your wallet if you want a sequencing panel and insurance won't pay. At my hospital, the list price for this test was $14,500 two years ago, but I got it cheaper, paying $700 out of pocket, by contacting the lab ahead of time. It's conceivable that insurance would pay in a case such as your wife, since doing a sequencing panel on the tumor might also give some insight into its origins.

Tumors that are MMR deficient or have POLE mutations are very sensitive to immunotherapy.