depending on how shy the baby is and the personality of the other one, well it depends
i have a very outgoing girl and a very very shy timid girl - both from the same breeder...the shy one is more work because everything needs to be done at a snails pace as not to startle her. she hunkers down when you go to pick her up, her ears go back when she is not expecting you to make eye contact, etc she is such a sweet girl though and not aggressive
if you do go with the shy one, it might take more patience and awareness. i need to make sure i am extra aware of my shy one when the kids are playing otherwise she would never get attention because the other ones all jump in my lap and jump in my face to give kisses. i need to be extra cognizant to give her equal attention because she is not as pushy as her siblings