I just wanna say hey to everyone!!! My lover and I have a 12 yr diff in age!

We have been together for over a year now. A few months back he asked me if I wanted kids (he haves 3 kids) I said yes at least 1. Well ever since we have been ttc. His oldest daughter who is 9 does not like the idea of having a baby around..its kinda sad...I really don't know what to say to her!! Any ideas ladies?