Relationships with in-laws can be tricky, and it’s not always about you personally. Sometimes, it’s about her own insecurities or unresolved issues with her child. Maybe she feels like she’s losing her son or daughter to you, and that’s hard for her to accept. I’ve seen this happen with friends—their moms just couldn’t let go of being the primary person in their lives. It’s also possible she has certain expectations about how her child’s partner should act, and if you don’t fit that mold, she might resent it without even realizing why.
Another angle is generational or cultural differences. If she grew up with strict traditions, she might disapprove of modern ways you handle things, like parenting or household roles. My aunt struggled with this—her mother-in-law constantly criticized her for working full-time, calling it 'neglectful.' It wasn’t true at all, but it stemmed from old-fashioned views. Try observing her behavior neutrally; sometimes, the dislike isn’t as deep as it feels. Small gestures, like asking for her advice on something she cares about, can slowly bridge the gap.