Here's how Bella describes her mom Renée: "Most of the time Renée was so bewildered by her own life that she didn't notice much else" (3.9). So when Bella visits Renée in Florida, where she lives with her boyfriend Phil, Bella is surprised to see how perceptive her mother is when it comes to her relationship with Edward:
"There's something… strange about the way you are together… I feel like I don't understand your relationship. Like there's some secret I'm missing." (3.23-25)
Bella manages to alleviate her concerns, but feels bad that her mother dismisses her insights so easily.
Although Bella mentions that Renée hasn't been much of a mother, leaving her to be the parent in their relationship for most of her life, Renée's views still have a big impact on her, especially when it comes to marriage. Bella tells Edward that she's been damaged by Renée's belief that marriage was the kiss of death for her relationship with Charlie. Although she admits that it's just something she's heard not experienced herself, it's hard for her to pull herself away from the fears her mother instilled in her. How might Renée react when Bella reveals to her that she's getting married? Will she be furious or will she be supportive?
For more info on Renée, check out her "Character Analysis" in Twilight.