How can I include my sister in my wedding when I don't like her?

So… I’m getting married next October and I’ve asked my baby sister to be a bridesmaid. Problem is… I have another sister. We used to get on but basically, she’s not a nice person. I love her dearly but she’s a horrible friend and she’s hurt me badly, which I’ve forgiven but not forgotten and I don’t include her in my life as much any more. But… now, my mum wants me to ask her to be a bridesmaid.
I don’t want to. She despises my best friend – who is maid of honor – and the feeling there is mutual. So I really don’t want them in a situation where they have to be in close company for most of the day as I’ll be stressing about it.
SO… how can I include my sister to keep my mum happy and stop a family feud but not have her be a bridesmaid? Help!