I'm a native speaker of English. I lived in Germany in my twenties as a military wife. My general understanding was that having two children in Germany as a single mom was the sweet spot for the benefits system. You were financially better off with two kids and no job than with one kid and no job. (Or so I was told.)

Single American soldiers were generally understood to be targets of local German women hoping to have another child without much risk of long-term entanglement.

So, yes, I took the line literally as "She will sleep with you to intentionally get pregnant and is merely using you as a sperm donor."