If she is someone you can talk to about these things. What I mean is, do you and your mom have a pretty good relationship, or does she have a better relationship with your sister? Maybe she can see where either of you are coming from. I mean, since she is the mother to BOTH of you, it may be hard for her to be biased and may give you a pretty honest opinion.

Otherwise, I'd tell sister to shove off, she has NO idea! Ok, you can put it more delicately. LOL! (which is what I have told my childless brother, who is 28 and has never had a serious relationship with anyone. HE told me that HIS wife would have the baby at home. LOL!!! HE has NO IDEA, can barely care for himself, has never even babysat and I would NEVER leave him alone with my children because of the fact).