There are tons of people who call to Jehovah but are not officially a part of the organization of Jehovah's Witnesses. These people might have studied but never progressed to baptism, might have family members who are witnesses, or might have grown up knowing the religion but never joined.
Just because her faith (meaning what she's grown up knowing) is associated with Jehovah's Witnesses doesn't mean she should be subject to scrutiny the same way a baptized witness would be. Besides, we shouldn't be judging people anyway. I love Serena Williams. She's my favorite athlete, Witness or not.
Anyway, I've said my peace.