So I previously thought that if both parents manifested a talent that the baby would always inherit that talent... That's what I've been told and it makes sense, but when you have worked to accumulate $75 of things to train your pet through that one last epic-mega stage because you think you're getting that talent for sure then you end up getting a pet that I might as well trash or sell.
Nope, there's chance involved at every stage. Talents are limited to the pools of both parents, but they can be the hidden slots as well is the ones you see.
if you have 4/5 of the talents you want, you shouldn't trash or sell it. Use it for now, and hatch it again for the missing talent. You'll get it if you keep trying.