My husband and I both love the names [name_f]Milla[/name_f] and [name_f]Isabelle[/name_f]. We both prefer [name_f]Milla[/name_f] and were pretty happy to go with that name as [name_f]Isabelle[/name_f] is the middle name of my husband’s niece we thought it would be good to go with something completely different. Then a friend of mine has just had a girl and named her [name_f]Milla[/name_f]. We’re not best friends, we actually hardly see each other anymore as we don’t live in the same town. However, she does live in my home town and we have always thought we would move back there one day, so our daughters could go to school together. I’m just trying to work out where people draw the line on having the same name as people. I’ve always thought avoid names already used in the family and close friends, but wanted to get other people’s opinion. I just don’t feel quite right about using the name now.
These names are common so to me it is a moot point. [name_m]How[/name_m] many Emmas can you know and still name your daughter [name_f]Emma[/name_f]? It does not seem a problem to me. Once they go to school and meet others of the same name, it is moot.
If the name in question were [name_f]Ludovica[/name_f] [name_f]Tangerine[/name_f], I’d say different. 
I agree there’s a different threshold for less-common names, but at least where I live [name_f]Milla[/name_f] would be pretty unusual. Whether they’re very close in age also makes a difference to me — even a handful months apart seems different from being born the same month. Ultimately, it’s probably about your own level of comfort, since the main reason to avoid it would be the perception of “copying” or “stealing” a name. If everyone feels pretty easygoing about happening to like the same name, then it wouldn’t need to be a problem at all.
Whenever you want. I don’t know when people started getting up in arms about cousins and siblings and friends using the same names as them, but it’s really quite silly.
The worry of appearing to be stealing or taking a name used by someone you know, is not a good reason to avoid using a name. I would not use a name already used by my immediate & close family members (and I do mean close!) and very close friends. I have a friend who is like a sister and while we now live on opposite sides of the country, I would not use any of her children’s names. I also have very close friends who I see on a weekly basis and I would not use their kids names. I would not worry about a not so close friend who I don’t see much, even if there was a chance our kids could go to school together one day. I also would not consider co-workers, neighbors, etc.
I would ask your friend how she feels. And if you aren’t close enough to ask her, then it shouldn’t matter. I understand the worry, but you shouldn’t pass up a name you love just because someone you aren’t really close with used it.