When I was a working mom, I did the shopping by myself because my helper took care of 2 kids and I didn't want her going to the market with them. She just brought my daughter down stairs to catch the school bus everyday.
I am a fulltime mom now and my helper goes out only when it is necessary, not everyday.
I think your helper is not too busy and feels boring in the meantime. Buy some cook books for her and start to teach her about taking care of baby to keep her busy.