Keep our nanny or let her go? Advice needed.

[Anonymous]

We've had our nanny for a year and half and, while she wasn't the nurturing type we were looking for, we found that she provided a good balance for our toddler. Now we have a newborn in the mix and feel that the lack of nurturing is becoming a problem with regard to her care for the baby. We want someone who will want to hold, rock, sing to, kiss and play with the baby but she clearly doesn't look like she has the patience for that. She hasn't dropped the ball on anything or committed any actual "fault", but my heart breaks for my little baby. My toddler had a nanny who was warm and nurturing and she moved out of state when my toddler was 18 months - I would like for my infant to benefit from the same type of care.
I work from home so I'm here a lot but I'm unable to get things done these days when I hear our baby cry and our nanny mechanically trying to soothe him or when I see him playing by himself on the floor while she's sitting next to him. I don't know if she can even change - can she? If so, how do you tell someone you want them to switch from being cold to being warm, and from being stern to being nurturing etc? Is it time for her to go and for us to find someone new? My toddler likes her but doesn't love her so wouldn't be devastated if she left and she's starting preschool soon. I feel horrible for the nanny though because I would hate to threaten her livelihood - she's finally able to afford healthcare with the pay raise we gave her for caring for two children. So, I don't want her to end up in a bad place, but I'm also not willing to have my baby receive care that is below my expectations (which are not unrealistic based on a previous nanny performance). Please help me come up with a sensible approach to either give her one more chance (if you think she can "change") or how to move on gently. If she were to "change", would the baby benefit from the increased warmth and affection even if it's not genuine? Like I said, I'm home 80% of the time.

[Anonymous]

This is the second time you've posted this. Apparently not enough people told you to fire her last time, so you're posting again in the hopes enough people will this time. So let me start you off the way you want.

Fire her. Happy now?

[Anonymous]

OP here. Thanks but that's not what I'm looking for. I'm looking for advice from other parents who may have faced a situation where a nanny who was once fine is not a good fit anymore. I'm also looking for concrete examples for trying to make changes with her or for opinions telling me change is not possible. If change is not possible, I'm also looking for advice on gentle ways of letting someone go (how much notice, severance, etc.) to be as fair as possible to our nanny.
In a nutshell, I want to be fair to my kids first and to her next because, despite the problems, she's still a nice person and someone I care about. I just care about my children more.