This is purely hypothetical as I'm not pregnant, but I have been wondering about dc2. 
I love fifi as it is what we call one of my family members instead of Fiona. She has downs syndrome and is the sweetest person you could ever meet. I would love to name dc2 after her if we have a baby girl one day, as I think it would make her feel really included and special.
The thing is, I don't like Fiona. Could I call a girl fifi? Or how about fidelia shortened to fifi?
I think my views are clouded on the name because of its original owner, but I wouldn't want to give a dc a name that others would think is silly.