Am I wrong?

So My sister-in-law has been seeing this guy for about 4 to 6 months now. The weekend they tell me that they decided to wait until after St. Patrick’s Day(They are bare very big drinkers and his family go all out for the holiday) And then they’re going to start trying to have a baby. They do not plan on getting married until next fall so she could be six months pregnant on their wedding day if she gets pregnant right away. She says she wants to start trying so soon because she doesn’t know how long it will take her to get pregnant and she’s 32 she’s ready to start a family. She is also very concerned that her brother and I will start a family before she will. She wants to have her parents their first grandchild and that is why she’s in such a rush to start trying. I told her she shouldn’t be concerned about us and that she shouldn’t be trying to start a family before she’s married if that’s the plan anyway she can wait Until after she’s married. It shouldn’t matter if we decide to start a family before she does that is no reason to start a family just because you think you may not be the first. She hasn’t really talked to me since. I don’t feel like I’m wrong. We’ve been married for two years and on our wedding day she told me that I had to wait for her to have children so she could be the first one to give her parents a grand child. At that time I was so shocked I didn’t say anything. I never planned on waiting for her to have kids.