The devil works hard, but that headmaid is working harder to get herself into troubles. It seems like she's desperate for recognition and projecting her own frustrations and insecurities onto Chloe through bullying... Makes sense though, bullies really are like that, but some smarter ones would be more manipulative and fake it to make the victim unaware of it, or at least stay low when it's exposed in order to avoid getting into troubles.
@Vikingboogers , I think it's largely because nobles of higher status can employ non-family-head-successor nobles's children (generally means children that is not the 1st son, they don't have nobility status after becoming adults unless having great achievements and given the status, or married to a noble) as important subordinates in their house, like head-butler, headmaid, personal knight, knight captain, secretary/assistant, advisors etc. In this case, it's probably a not really influential/rich/powerful Count's daughter working for a Duke as a headmaid. In some cases, it's quite honourable for lower nobles to have their less-important children to work for higher nobles because it forms a connection, especially if the higher nobles are esteemed and powerful ones.