When Arya was born, we had her get Bastian a present. He was very excited about that. I also involved him. Get the diaper, etc. And I hyped up that this was "his baby sister," not "our baby." When introducing her, etc. "This is Bastian's sister Arya!"
Also, make it a point of making the baby wait when feasible and announcing it. There's so many times when you'll have to make the toddler wait because the baby needs something. So, if I was, like getting Bastian dressed or something and Arya started crying I'd loudly saw "Arya you are just going to have to wait, Bastian needs Mommy now."
Bastian was a bit older, 2.5, when Arya was born. But I think all this helped because he is extremely protective and loving toward her and has been from day one. We never once had a return-the-baby moment.
We also kept his routine exactly the same. Gymnastics, music class, etc. nothing changed for him. I even had the baby in a sling and took him to gymnastics three days after she was born. That may not be feasible depending how the birth goes, but if your daughter can't, then others can try to keep things routine.
Q