As far as I know, family members haven't been on the TV show in person, in some episodes you could see photos of them, like Sakacchi's grandma, and Su-chan's dad on "Back to the Idoling". On uRa episodes, they show Manami and Ruka's mothers when they went to NGK in Osaka. Sakacchi's entire family more or less was shown on her adulthood ceremony episode, that's pretty much it I think. There's a rumor that Miyake's sister was among the studio audience and was caught on camera, but that is pure speculation (the rumor started because her looks resembled Miyake.), I can't remember which episode that was but it was fairly recent. You can also see Amimi's sister on Amimi's blog, she looks younger than Amimi lol.