Two Kinds of Bridesmaids
There are those without experience and there are those who has been a bridesmaid before. Those who are first time bridesmaid mostly feel excited and overwhelmed by the invitation to be one of the members of the bridal party. They are mostly cooperative and just happy that their close friend remembered them to join in.
For second time bridesmaids, they already know what they are doing and they know most of their responsibilities thus it will be easier for them to participate in the task given to them. They also understand their value and the support that they should give the bride since the bride will constantly need them.
For brides choosing their bridesmaids, it does not matter whether it is the first time or whether their friend has an experience in being a bridesmaid. What matters is that their friend is willing and cooperative to the task given to her. Your job on the other hand, is to provide great bridesmaids jewelry gifts to them so that they can feel that you are truly supporting them.