I know your question was about borders but I couldn't help noticing your background also forms a star and yours is a mixture of pink & white points. Was wondering if maybe you would like to turn your blocks to form alternating pink & white stars? Just a suggestion which may not even be possible. I did see a few white stars and I particulaly liked the one with 2 pink & 2 white points in opposite directions, the one at the top right side, second from right. Whatever you decide, your quilt is beautiful !!!!