Congrats on the hatch

If anybody cares about the parentage- just tell them they were from a good family.
About the downers:
I agree about building your own soil. throw all the leaves, cut grass, etc. and the animal poo in a pile and make your own soil. If neighbors put their lawn clippings on the curb- grab those too.
Another idea- Many communities compost yard waste and let residents have it for free or cheap. Usually it's bring your own vehicle and take away however much you can carry. Some communities will deliver the compost, but you'd have to check on what they charge. You might trade favors with somebody to get a load for you. I've planted in almost straight compost and had happy plants in that bed.
You can also ask lawn service people to dump yard waste at your place. They usually have to pay to get rid of it at the dump, so they're usually happy to say yes. Grass clippings may have lawn chemicals on them, but removed trees, are less likely to be sprayed. Some people get incredible amounts of free mulch that way.
About kids- I don't want this to sound harsh, but your way of viewing the situation might be making you more frustrated. Those feelings could be making it harder to find possible solutions.
I know it's hard to be objective on this subject but . . .
Are you more interested in passing on your DNA, or in nurturing? Either way- there are ways to get at least part of what you need.
If you really want to pass on the genes- you might help friends that are challenged conceiving. There are plenty of people that want babies and need the other half of the genetic material. If it's a friend, you might work out some kind of arrangement to see the little one growing up. Sorta like an "open adoption".
It you just want somebody to nurture- maybe adoption, fostering a kid, or volunteering/working with them?
My body doesn't make kids, so I had to find alternate ways of handling that side of myself. I was a great babysitter. I considered adopting before, but want a real home and to not be struggling financially first. That hasn't happened yet . . . Some pets have been my furry kids too.
Good luck.