The brunette royal, who was known as Kate Middleton prior to her 2011 wedding to Prince William, has a close bond with her mom and often consults her when she needs advice.
Sources close to the family say Carole was on hand recently after 32-year-old Catherine received a backlash for her and William's spending, which has apparently angered Queen Elizabeth II and Prince Charles' wife Camilla.
"Carole's a problem solver and is confident in her ability to deal with any crisis. It must sicken her that people criticise Kate after all the sacrifices she's made, but she knows complaining won't make any difference," an insider fumed to British magazine Woman.
"Instead she's ploughing her energy into fixing the situation, so she's told Kate to open her eyes - and never get complacent."
Catherine is Carole's eldest child, and she along with husband Michael are also proud parents to Pippa, 30, and 27-year-old James.
Carole apparently still sees Catherine as her little girl, but has put emotions to one side in order to help steer her daughter out of the current situation.
"Kate appears determined not to undo all the good work they've out in already. She's listened to Carol, who's told her to just be herself. After all, William and the country fell in love with her as regular girl - not a duchess," the insider added.
Catherine and William put apparent worries aside earlier this week and looked happy as they celebrated Prince George's first birthday on July 22.