Do I owe them anything??

Back story.

Okay so with our in laws side there is me and my my SIL’s pregnant all within weeks of each other. Anyway I’m the last one to find out the gender as my baby is the youngest out of the three. The other girls did a family gender reveal, one having a girl and the other having a boy. We go for our scan in two weeks and they are asking when our reveal is. Thing is we don’t want one? In fact and we told them we want the gender to ourselves and only us. (We live far away so it’s easy for us to keep this a secret too) but I got told it’s not fair they have announced and not us. Even got a message from my partners nan saying I owe the family this because it’s the “tie-breaker” I’m feeling bad but I didn’t ask them to tell me their gender this is our choice and shouldn’t be making us feel like way about it. Am I wrong and do owe them at least this? Or can they just get over it.