In The Truth About Forever, Macy and her mom just do not communicate. And they haven't for almost two years. They're both totally aware they aren't really done grieving, but neither one wants to let the other know that things are tough. So what does it take to get them to finally open up? Wes's probing questions a boatload of chaos, apparently. And probably—we're guessing—time to heal.
Macy and Deborah might both be bad communicators, but the blame falls on Deborah. She's the mom, and it's her responsibility to talk with her daughter.
Open lines of communication wouldn't have helped Macy and her mom, anyway. They just needed time to heal.