How do I befriend my sister-in-law? We are not the best of friends, but I want to maintain a cordial relationship with her. Any suggestions?

I know how you feel. I don't particularly enjoy the company of my SIL either. She's very competitive and at times, condescending. So whenever I see her, I don't talk about myself or my life but instead I let her go on an on about her "perfect" life. Just be patient and stick to neutral topics. You can also try going on double dates with your husband, his sister and her partner.