There are more appropriate ways to say this:

"Nobody with kids. I might want kids some day, but I'm not ready yet, and it feels like there would be too much pressure to either be involved with her kids or be cut out of a major portion of her life until we're really serious. And again, not ready.

And somebody athletic, since I'm into biking and hiking and other activities that require a certain level of fitness.

And... well, somebody who isn't into the whole casual sex thing, honestly. I think sex is special and, for me, requires a strong emotional connection. I want someone who has similar views on sex."

See, I feel like it changes it when you're not focusing on the other person, but yourself. I'm not ready for kids, I'm into fitness, I'm a demisexual. It sets up the same thing without disparaging people who aren't what you're looking for.