I love
Catherine, its a nice elegant, timeless name. If
Grant's niece wasn't named this I'd consider if for a future daughter (I might consider it as a middle name but spelt
Katherine so my sister-in-law doesn't think I've 'stolen' her daughter's name).
Catherine or
Katherine are my favourite spellings, I prefer
Catherine slightly more though. All the other spellings don't look right to me.
I cannot stand Cathy/Kathy as a nickname. I don't mind Kate/Cate but I much prefer Kat/Cat or try and convince people to call her
Catherine all the time.
Olivia Catherine is nice.