TikTok / @justmom1984 Composite

The mother of Anna Kepner -- the 18-year-old who was murdered on a Carnival Cruise ship -- is questioning the sleeping arrangements her daughter was placed in leading up to her tragic death.

Heather Wright told Fox News she's been villainized in the situation, but it's Anna's dad, Christopher Kepner , who could be partly to blame. TikTok / @justmom1984

Anna was reportedly sharing a cabin with two other teenagers -- one of whom is her stepbrother, who's now suspected in her death . Anna's grandmother told ABC News the teenagers chose the arrangement themselves ... but Anna's biological mom seems to think an adult should have vetoed it.

She said, "Why am I the bad guy? He put them in the same room together."

Remember ... Anna's bod

See Full Page