Side work for maternity leave

My husband and I are due with baby #2 at the end of December. Our first will be almost 2 years old. We both work full time and live paycheck to paycheck. I can take up to 4 months of maternity leave but its not paid. My husband thinks I should find a family to nanny for/watch their kid a few days a week during maternity leave to make some extra money. I'm worried that it will be a big change from watching 1 kid to 3 kids but the extra income would help! Anyone ever done this? Advice? Other ideas? Tyia