Yes, i have the same dilemma. We use the senority rule. I was in first, so I get to choose, usually. Unless it is the night he's on call for driving the ambulance. I do try to keep it fair. Having a teenager able to babysit helps. and our middle daughter is in 5th grade, so sometimes we let her watch her younger sister (if big sis isn't home) if it works out (no running around to do, dinner in the oven, ect) We also have neighbors that we couldn't live without, they say- just go, and have the kids walk over. I call first though if i have time.
My husband and I both volunteer. We have two boys, River is 5 and Lochlan is 9 months. Actually I have been told or "asked" by my chief to not do interiors til the kids are older. Husband doesn't want me to ever do them. I am just biding my time, taking my training, getting certs, and when the kids are older, it will be my turn. I do fight them from outside and when it comes to grass fires or wildland that is my territory. It is good to have an older neighbor next door that can sit with the kids. That is our life saver.