None are turning brown. One set is curling at the tips, the other is curling/getting wavy along the edges of the leaves (not the tips)

I also have one of my spider plants curly, but it's been like that since it started coming from the mother plant (later I separated them). No brown tips either,....just wavy leaves...I think it's kind of cute, and it goes with my curly hair :)
Maybe there's nothing wrong with that? I guess I'm not help at all, but just wanted you to know that I also have another curly plant, that is otherwise healthy.
Rocio

I have LOTS of spider plants, and sometimes a baby separated from the mother will turn out curly others not. I notice the green with the white strip in the middle is more prone to do this then the green or the green with white strips at the side, they seem to grow just fine either way. As I take my houseplants outside for the summer every year when I bring them in they get the brown tips, the new that comes on don't do this however, I did mess up this year and I put a plant spike in one of them at the same time I brought it in, almost lost that one, started to completly burn up, had to remove it from the soil, wash the roots off and put it in fresh soil, it is coming back now just fine.

I think that there's a type of spider plant - a variation on the common ones we see - that is curly, so curly offspring are not that far-fetched, though they may be rare.

Yes, there is a curly spider plant now, Exotic Angel grows them so they are common at Big Box Stores.

Are Spider plants sensitive to drafts causing wrinkled or curly leaves?