I went through that dilemma all the time when I take in a Porch Cat, as I had Ebony Beau Tubster in, and he had both FIP and FELV so badly that he had to be PTS
And I once had Gem in, and he passed on as well from the same things, so thats FIP iin my neighborhood
I am praying that that Little Siamese can be adopted and can become a Great Cat Companion.

She will have Chloe as a Guardian Angel for certain , and the Siamese Six Pack as well