First of all CONGRATULATIONS
My sister just had her first baby in April and her yorkie Bogey will be turning 4 in December. She was worried that he would be jealous, but he's actually been really great
He's very protective of his little sister and has to check everyone out before they can hold her or be near her. He sleeps in bed with them and when the baby was first born he would get up and sleep in her room while she was being fed, but now he just stays in bed.
My sister made sure that before they brought her home to take a blanket that the baby used in the hospital home to Bogey first so he could smell it.
Now, my mom has two Yorkies, Max doesn't really seem to notice that the baby is around he'll smell her and her things but isn't really interested. Mazie on the other hand is very jealous and whenever the baby is over, which is at least 3 times a week, she will sit on the opposite end of the couch and pout.
Lucy, who is 4 months, who was actually born 10 days before Brooke, is very curious about her, last night he jumped into her car seat with her and licked her all over. It's funny how dogs can sense a baby and know how to be gentle, because she always is very calm and gives Brooke kisses even though she could be nipping at us moments before.
Good Luck