Part-time Tue/Thu sitter for 4 month old - starting mid-May

We're a family of 4 with a newborn/infant boy (our 2nd) that will be 4 months old at the time we need to start some part-time child care coverage. Dad (me) will be primarily on parental leave during this time frame, but needs two predictable afternoons a week to maintain my business. Both parents work from home and mom will very likely still be breastfeeding during work breaks. Sitter will need to provide primary care during the hours of 11:30am-4:30pm on Tuesdays and Thursdays. This time will likely also likely include mom breastfeeding at least once and he'll be napping probably a little less than half the time. We're hoping for someone to take good care of him during those wake windows, provide some stimulation and play, maybe taking him for a walk (if it's not too hot over the summer). We're located in Beacon. Thursday afternoons are the essential anchor of the schedule, but the other afternoon can be another day as long as it's predictable and scheduled (it doesn't have to be Tuesday, but I would prefer it to be Tuesday). Very important for sitter to show up on time, as some scheduled meetings will start at noon.