My sister usually has her cloaking device on...so if we're online together, I can't see her, and she won't respond until she's darn good and ready! LOL!
But that's the way she has always been, so that's OK. If she wants to talk to me, she will. Otherwise, she totally igs me.
As a friend once said, "Sisters are weird. I know, I'm a sister."*
*they said it with one of those weird smirks.