After coming home from the hospital with my newborn, I found a note from my mother-in-law, Abigail, on the table. Expecting a sweet “Welcome Home” message, I instead found a demand for $600 for taking care of our dog, Rich, while I was in labor. My husband, Jake, promised to talk to her, but I had a different plan.

A few days before I went into labor, I asked Jake to check with his mom about looking after Rich while we were at the hospital. She agreed, and we thought everything was set. But when we came home, there was that note, demanding payment.

I wasn’t about to pay up without a fight. A week later, when Abigail visited to meet the baby, I handed her an “itemized invoice” detailing every favor we’d done for her—helping her move, paying for car repairs, and babysitting. I pointed out that family doesn’t charge each other for favors, and if she expected payment, so did we.

Abigail was furious, stormed out, and we never heard about the $600 again. Jake was proud of me, and I was content knowing I’d put her in her place. If she ever tried again, I had the receipts.