I don't know about anyone else but I just wouldn't go if I was asked by some pimple-faced attendant kid. A simple, "No, I'm staying. I'm family," would be my response
This happened at a wedding I attended. The JW woman getting married had a sister that was a "disapproved associate". Well, she attended to the wedding but was not in it. Then she came to the reception. The attendants asked her to leave and she refused. Saying she would only leave if her sister or the groom asked her to leave. Several elders attempted to convince her to leave but she ignored each one but her non-JW family didn't. The elders had the ballroom stop serving the remaining tables. The elders left and many followed right behind them and said some not-so-nice things as they walked pass her table. We stayed because we wanted to see what was going to happen.
Most of the guests left and then the bride was crying and finally went over and asked her sister to leave. Her sister and everyone at the table left but by that time they only had about 30 min left for the reception so the remaining guests headed over to nearby restaurant. The whole ordeal lasted for more than 3 hours during which no one ate (except non-JW family) because a "disapproved associate" had entered the room. There was only time for the new couple's first dance before everyone had to leave the ballroom.
I'm sure the only reason the bride waited so long to approach her sister was because her sitting at a table filled with non-JW family members. That didn't stop the elders from approaching her and asking her to leave.