EL, I do not have in-laws and my mum is taking care of my bro's kids then. I had been depending on domestic helper 1 month before birth. My girl is 5 this year, this is my 2nd helper, she been with me for 3 years, has just renewed her for 2 years. My previous helper was ok for the 2 years, started to slack after she came back from homeleave and I've changed by the 8th month of the 3rd year. Last time, I still asked her if she is ok to take care of no.2 then I plan, initially, she told me ok, subsequently, she told me no and I respected her answer!!! After that change, I told my HB, I'll change every 2 years, I'll do the training all over again every 2 years!!! However, my current is good, therefore, I stick by her.
In my opinion, you should let her go. Have you ask her about additional chores next year?
I'm pretty "structured", she has a hourly schedule for the whole week!!!!
My expectation is straight forward, take care of my girl (MUST)and 2 dogs (MUST), household chores, cooking. We need to set our expectation and match it. I do not have CCTV at home to check her movement, I believe in mutual trust and treat her like my family member and she knows that.