Conception Lore

[Annana]

Side quest spoilers from Stormblood.

Well, there is a sidequest where you can help a Garlean solder (hyur) hook up with a miqote.... they even mention 'the pitter patter of little feet'. So I assume they can interbreed.
THere is also a sidequest for a lala male and hyur female that met on the battlefield and are in love. No mention of children in that one, though.

Every race can interbreed, it just has a huge stigma attached to it and the chances of the child surviving are slim.

[Kyran-Varlsen]

Every race can interbreed, it just has a huge stigma attached to it and the chances of the child surviving are slim.

I did the aforementioned quest, but I was under the impression that the given statement could be interpreted as either "get kids the old fashioned way" or "get kids even if we have to adopt them." If the latter is possible then the statement might not be as useful a factor as we would hope.

It is a bit frustrating that there does not seem to be a clear statement on the matter. Certainly your given reason would satisfy the matter if it came from an official source.

In the case of Hilda, the devs were throwing out a half-elf, which is a fantasy staple since Lord of the Rings. But the Au Ra/Hyur Union is the only other mentioned instance of interspecies relations that probably produced kids - and even this might be a tale according to the teller.