Mom didn't dilate with me. Is this hereditary?

My mom keeps telling me how she would not dilate with me and how that is probably going to happen to me too. I'm 39 weeks and everytime she says this it stresses me out. We are doing a VBAC, our first was emergency c section bc he was breech at 30 weeks. I have half a uterus and am so blessed to have made it this far and really wanted to have a natural birth. Both my grandma and aunt had natural births, so I don't get why she keeps saying I'm gonna end up like her. My brother and sister were planned c section, so they never gave her the opportunity to try again. Just wondering if anyone has experienced this or not or if I should be worried.