Re: Play date etiquette ??
Well, OP's original post did not indicate that this person was a complete stranger. No, I wouldn't drop my 6 year old off at a complete strangers. However, I also would not bring my 4 additional children there. I agree with other posters -- offer to have the playdate at your home and invite the mom to stay for coffee. Or have it at a park or other play place. It sounds like you could really use some additional people in your life given your friend moving away. This is a great opportunity.
However, my daughter is 7. She has several friends from gymnastics. The moms and I usually stick around and chat while the kids are practicing. At this point, I would very likely let my daughter go to a drop off playdate at the homes of the girls she is becoming friends with.