Am I being rude??

I'm staying anon because I am super unsure and don't want everyone to think I'm a monster.

I'm getting married. And ever since we got engaged my fiancés older sister has just come across as cold to me.

She makes it known that she doesn't like a lot of things Ihave said or done or suggested for instance.

She hates the venue we picked. Even though we both picked it. She was mad that she has to take a day off work because we have decided to get married on a Friday because it s little cheaper for us. She thinks it's a bad idea that we move to a different town - telling my fiancé that if we move, that he is abandoning his parents. She cried because I didn't ask her to be a bridesmaid. And now (please dont think im awful) she announced she is pregnant and told my fiance that we need to change our wedding because she will be at the point where she could go into labour at any time when its our wedding and she doesnt want to be far from home in case the baby comes.

I said no we arent changing our wedding day. She pissed.

What are your thoughts.