M.W.
I definitely think a raise is in order. A bonus is nice, but it's a one-time thing. A raise is permanent and shows your appreciation in an on-going way. Personally, I applaud the fact that you acknowledge the positive effect your nanny is having on your family. Too often, childcare providers are taken for granted, taken advantage of, and not compensated fairly. (I should know. I watch a 2 year old in my home while my 3 kids are at school. She loves being here, and my family loves her, too, but if her parents appreciate it, I wouldn't know...no raises or bonuses have ever come my way!)