I have one who is 5 and know no others locally. None at her school. She is a Tilda. I don't like Tilly at all and thankfully, neither does she.
I have a ds with an uncommon name and there are going to be 3 in his class if we/they don't move. I made the mistake of teaching a parentcraft session when he was 11 days old and two of the couples heard and liked the name so used it. Just goes to show...