Airbnb plus walmer

I booked a Airbnb in walmer two weeks in advance and paid in advance. The owner asked me to cancel a day before because she didn’t know I was travelling with a toddler while I specified when I made the booking am travelling with a toddler. I lost part of my booking fee because I had to cancel less that 24 hours before my trip . Am disappointed in the way Airbnb has been handling this .