Need mama advice

My mother in law is staying with us. She was supposed to be going home Sunday, then today and now it's next week. I'm nearly 27 weeks pregnant and I am exhausted all the time as well. My step daughter is here for what was going to be a day now to 2 weeks. I thought my mother in law would help but she has me up and doing things. I am beyond exhausted! My sister in law is 10 weeks pregnant and it's always 'shes so tired let her rest' 'or poor her it must be rough'. How do y'all momma's handle being pregnant with a hyper 8 year old that wants you to do everything with. Because this girl is running on fumes.