'Ladybug' sounds American to me and Wikipedia concurs:
"Coccinellids are known as ladybugs in North America, and ladybirds in other areas. Entomologists widely prefer the names ladybird beetles or lady beetles as these insects are not classified as true bugs"
Her daughter is adamant it's Ladybug...
Just hoping that I can get enough answers to show her and see if it helps.
I did consider Ladybug as American terminology though