I've written to you a few times and have used the website a lot. I have a different question I'd like to ask. How do you deal with things that aren't sinful, when they resulted from sin? I know the Bible doesn't say that, for instance, if a woman gives birth before she is married, she is required to give that baby up for adoption. So I think there is some allowance for using, benefiting, or enjoying the outcome sometimes. My question isn't about having a baby before marriage, that's just one example. Are there times we shouldn't use something because it wouldn't have (or might not have) come about if we hadn't sinned? If we repent of that sin, should we still feel the guilt when we are still benefiting from a result?
The general rule is that good doesn't result from evil. "And why not say, "Let us do evil that good may come"? -- as we are slanderously reported and as some affirm that we say. Their condemnation is just" (Romans 3:8). Sometimes something appears good in the short term but has negative long-term effects.
Let's use your example of a girl committing fornication and having a baby. Yes, there is pleasure in having a child, but there are also difficulties. A single mother has to support herself and her child, so she can't do a good job at both. Usually, the guy doesn't stick around to support his child. Children raised by a single parent tend to have more problems because that parent can't be always available. The list can continue, but my point is that what looks like a benefit isn't as fun as it may appear on the surface because we have a tendency to gloss over the bad parts.
How about another example? Stealing gives the apparent short-term benefit of wealth, but in the long-term, it leads to prison. The short joys are not worth the long misery.
Generally what happens after sin is additional responsibilities. Sure there are aspects that are enjoyable, but not nearly as enjoyable as they would have been if we did things God's way.