Don't know if this is the same... but I felt the same way when I got my 2nd Yorkie... thought I'd be neglecting the first. I was surprised... there is more love in my heart now, esp since I now have 4! They come to me individually when they need a hug or to be held... the rest of the time they seem very content. I think your Yorkie will understand you putting your child first, as long as you can still find a few moments throughout your day to make special time just for her...
Oh and congratulations!