Ugh.  Neighbor girl, my daughters BFF, just rang the doorbell, wanting to play.
Sorry, kid.  Not today.  Not until we can get our plans in place and we can make sure your parents are taking this as serious as we are.
I think our policy for the next couple of weeks is this:  they can play, but only outside.  Bike rides, walks, etc are all good.  Probably no to the playground.  No going inside, and no shared food/drinks.  And when you come inside, immediate hand wash, shower, and change of clothes.  Absolutely no hugs (probably the most important bit).
At the end of the day, its not just about us - the neighbor girl has elderly grandparents a couple houses down and her mom is recovering from cancer.  My kids are currently coughing a little bit - Dr says sinus infections, no fever....but obviously no corona test so who knows.
ETA:  also loosening up on screen time restrictions. These days, I'm actually encouraging my kids to be on their phones and not playing with their friends.  My 5th grader had spent pretty much the whole day in a group video chat with her classmates.