Yeah, it's just per chase by chiyo, but I was able to grind use out of her till lvl 83... as others have noted by the time you can access Kage treasure it's a good idea to start preparing to replace ASAP or you'll end up like me behind the curve for almost 13 lvls/2 months.

As a chain slave she works great with virtually any main and GNW 1010. I happened to use a 3star Hinata as a meatshield to prolong Chiyo's shelf-life.