I have a Daisy too and just two weeks ago brought home a male puppy. She was a little scared of him at first, then was happy to have someone to play with.... Sometimes she gets jealous and will jump in between us if I am giving him attention but I just give her love then too and she feels better. At times she is a little ruff with him and I have to watch them play but he is starting to give it back to her.
In the last week they have started to cuddle and she is protective of him, like when he cries when I wash his face and groom him. She is right there like a worried mommy, lol
Here is a chart from one of our members websites that has a chart to "estimate" the adult weight of a puppy.
http://yorkiepassion.com/growthchart.htm
All the best if you decide to bring home another bundle of joy!