Navigating childcare as an on-call doula?

I have a 5 year old who is in school 9am-4pm, and a 1 year old who is mostly at home with me or with a scheduled babysitter.

I am getting ready to leave my job to do birthwork full time. Ive been having a few clients here and there and mostly doing scheduled birthwork (postpartum, miscarriage support, etc.) but i want to start with 1 birth client a month.

Whats the best set up for childcare?? If i was called to a birth during the day time while i have my baby with me, I’m not sure what i would do.

My midwife has different sitters lined up on each day of the week for her kid, but he is like 8. Also she’s been doing this work for years and is at births often. I’m only getting started like one birth a month. I’m a little nervous leaving my baby with ppl he’s unfamiliar with too. Has anyone done this, or have other ideas?