My first language neighbour, more or less the same age as me, tends to refer to me as 'chi' if she texts me for any reason. I'm not actually sure if she says 'chi' when we're talking, though I always use 'ti' with her. It seems more friendly.
Her elderly mother lives with her and although she's really lovely and friendly, I always feel I should use 'chi' with her to be respectful. I've noticed a fair bit of 'chi' used between the older women at Merched y Wawr, so maybe it's hanging on with the older generation, but gradually going out of use with younger ones.
I think the woman serving in our local supermarket calls me 'chi' as well - possibly a respect for customers kind of thing. I'll have to make a point of noticing next time. I don't usually think about it!