I've had this little idea "What if Riley and Tim were together?"

And here it is, somewhere in distant parallel universe, happy uncomplicated family enjoying their vacation.

The girl on the left is their oldest daughter, her fur changed colour becasue of fathers influence, then twins sisters in the middle which are moms copy, and the last their youngest son who inherited moms eyes.

I imagine that when son was born Tim sighed heavily and said something like "It's boy! Finally!"

Also had this idea that in this world it's hard to make children between different species, but it's possible. Most common result would be that child is of mom's species, then they can inherit some minor atributes from father (like eyes/fur colour and etc), and then the rarest result is child would be father's race.

About hybrids. Hybrids can exist too, but if the parents are very very distant relatives on evolutionary branch, chance of hybrid being born is very very unlikely.

Snake and cat would have for example very little chance of having hybrid ofspring, while fox and wolf would have significantly more chances. Riley (the mom) is a hybrid between wolf and arctic fox if you didn't knew. And yes hybrids would be fertile.

So that's some of my thoughts on worldbuilding, I didn't thought it out thoroughly so might change in future. And the image isn't canon, just "what if"