http://www.cinemablend.com/television/1522900/the-flash-character-well-probably-get-to-meet-in-season-3

Season 2 of The Flash featured a lot of drama on family fronts, ranging from Harrison Wells and his daughter to the newly expanded West clan to Barry and his father figures to Cisco's sibling issues. One character who didn't get to spend time with family was Caitlin Snow, presumably because she was too busy either being wooed or kidnapped by an Earth 2 speedster. Luckily for Caitlin fans, Flash executive producer Andrew Kreisberg has revealed that Season 3 will probably introduce a major member of her family who was only mentioned in Season 2 during a chat between Caitlin and Killer Frost. Caitlin's mom is on the way. We haven't met Caitlin's mother yet, so we got a little talk between the two