Don't worry about it at all, my mum told me quite boldy that she did not liked Devons name as I named him at 20 weeks, well she had known before then as it was my boys named 9 years earlier when I had my daughter. My OH had also said he didn't really like it 9 years earlier. Don't let that stop you at all. I also have an older lady freind, i have known for years, and she felt she could be that honest to tell me she didn't like his name
My mum has not said she doesn't like it since the birth, but mentions i a proud way to people often, how at her cornwall garden society she had to go in an announce that she had a grandson called Devon!! My older freind, has said it since birth, , but she has a son called Kevin, so how is Devon much different to that name!
Luca is a lovely name, she will have to get used to it, she will want to spednd lots of time with him and when she sets eyes on him she will love him and his name, whatever you choose , so stick to your guns - Luca it is..