D.B.
I'm not a county social worker, but a friend recently had incredible service from the town DPW. (Town employee vs. county, but still government, so maybe it's applicable.) She dropped her keys down a storm drain, and he came to try to fish them out. When his magnetic extension pole wasn't enough, he went back to the DPW and got a bigger truck, drained the thing, and fished out her keys!) She went to the local pizza/sandwich place and got some things for the whole office. She also got a gift card for him, which he was allowed to accept as a tip. But in her case, it was just one worker.
We also checked guidelines for the letter carrier - they are allowed to accept something $20 or less in value if it's not cash. Again, that's federal and not county, but still...
In your case, I think a platter/basket of edibles would be lovely and not of sufficient value to any one person that there's a problem. Social workers are notoriously underpaid and overloaded with cases, and you are doing this after the fact rather than appearing to bribe anyone ahead of time to get to the top of the list, so I can't imagine there would be a conflict.
I'm so happy you got results in 2 months instead of 11! One less thing to be burdened with.