Holly.
Sometimes I don't think people appreciate how careful Holly had to be with how she presents herself on TV relative to the other moms, solely because she's black. She's obviously highly educated and classy and that's her nature, but when people question why she didn't really "get in there" and fight like people think she should have, Holly's smart enough to know that 100% regardless of whatever her true personality is - she'd have been painted as the angry black woman. I'm not saying Christi and Kelly, who did speak up more and were more vocal were portrayed as particularly flattering either, it's just I think sometimes when talking about Holly people need to keep this in mind. She did not want to give the producers anything, especially early on, to feed this stereotype. The show was made in 2010, post Obama's election and the treatment of Michelle by the media despite her well documented class and education proves that all that doesn't matter, they'd have latched onto ANYTHING she gave them.