How to cope

This is a long one! My husband and I got married in may (i am 23) and we decided to get pregnant and are due in May with our baby girl. My husbands niece who has always been rude to me and fake (who is 20) decided she was bored and got pregnant on purpose (with a guy that already cheated on her in their short dating time) and she is due in April. She had a court wedding this month to get that out of the way as well. My problem here is that this family acts like everyone is perfect and loves each other so much but are the most self centered competitive people I have ever known. ITS SO FAKE. I'm so scared my daughter will be compared for the rest of her life because everything I plan for my daughter, they want to do bigger and better for the other new baby coming who is also a girl. My husband and I did it all the correct way and I feel like we are living in the shadow of his niece who literally didn't do college, doesn't have a job, but lives in a fantasy land that life is perfect because mommy will pay for it all. I just wish they would all leave us alone and let me and my husband enjoy our daughter and stop trying to constantly compete. What can I do to get over this?