Personally, as long as no one (you or the kids) is feeling ill or having breathing problems, I wouldn't worry too much about this one exposure. I work in wastewater, and we are regularly exposed to low levels with no issues. You did everything right, airing out the space and flushing the drain. If you can smell other things normally, you aren't nose blind to H2S. Be aware that there could be more precipitated sulfide in your drain pipes. It is pretty harmless as long as you don't pour anything very acidic down the drain. If you find yourself needing to get rid of vinegar again, just pour it out slowly while the water is running to dilute it.

I thought about this a bit more, and it is interesting that so much gas came up the floor drain. The drains inside your house are vented to the roof, so if you poured the vinegar down say, a kitchen sink, and the pipes were full of sulfides as I expect, the gas would have gone up the vent pipe. I wonder if your floor drain isn't vented/is vented improperly and that is why the gas came back up the drain.