So Lindsay Lohan has a half-sister - big deal! Well, that's at least how the actress is handling it, anyway.

Lohan appeared on Friday's Good Morning America to promote her big comeback TV movie, Liz & Dick, and she spared few moments discussing her half-sister Ashley Horn, who was recently revealed by her father Michael on The Trish Goddard Show earlier this week.

When talk show host Amy Robach brought up the subject of her new family member, Lindsay responded, "I didn’t even hear that, so thanks for the news." Robach pressed on again and Lindsay was more adamant: "I  don’t pay attention to any of it. I can’t... I don’t really want to get into that because. I want to stay on the positive side of things."

When previously asked by TMZ about Horn, Lindsay said that "[had] no hard feelings towards Ashley but finds the situation 'disgusting' especially because Micheal had the affair while he was still married to (and having kids with) wife Dina."