Property manager expects me to come to her?

Just moved into a new place, realised the owner had some mail in our post box. I let the agency know and the property manager said to return it to them ASAP - it’s a 25 min drive from my place and I have a baby who is ill, my husband also won’t return it cause he comes home in the late afternoon. I haven’t replied to the manager because it’s unfair that I have to drive to deliver their mail, while having a baby too. What should I do?

Also if I return it this time I’m sure she will expect me to return more mail in the future to them.