It honestly depends on the helper as some needs pushing so coming up with a timetable will ensure all chores are done and not forgotten but if your helper has been with you for a very long while she would have her own work process so as long as things are done properly you can leave it to her.
I haven't created a timetable for her, but she has certain things to do on certain days, eg. make beds, clean kitchen, hoover daily. Then things like laundry, 3 times a week. It's pretty flexible :) as long as she gets what she needs to get done, I'm fine with it :)
We usually ask her to do certain things that need priority, say, cleaning the certain rooms and preparing meals, but other than those she usually does her own thing. And it works for the most part.
I let her know what needs to be done for the day and let her schedule it according to her own time. As long as she gets the job done, I'm fine with it :)