Freddie's sister's name is Kashmira. I heard she did a worldwide tour with a photo exhibition of Freddie's photos some years ago but I haven't heard anything about her goings on since.
Freddie's Mom, is very much alive and well, and Brian has been discussing in alot of the current interviews promoting the Queen+Paul Rodgers tour that Brian currently and regularly talks to Freddie's Mom and that she gave her 100% approval to the tour and told Brian & Roger that she was proud of them.
From The Capitol Gold Interview:
"I actually talk to Freddie's Mum as well, quite alot. And Freddie's Mum feels good about this, so that's kind of good enough for me. You know she said, "I know you guys are gonna make us all proud". and That's the way it's gonna be".
I also know that Freddie's Mom was a guest at The Royal Symphony's tribute To Queen conducted By Tolga Kashif, and her photo is ON the CD with Tolga Kashif.