Your mom was becoming a moth. She had recently made a large nest in the living room to protect herself as she becomes more moth-like.

So far she had white fur growing on her, the white wings on her back were fully grown, and her antennas were comfortably resting on her head being fully grown.

Her behaviors were slowly becoming that of a moth however she will remain human sized once fully changed and have a human lifespan.

Currently your mother was sitting in her nest getting comfortable. She was chewing on a wool shirt slowly eating it.

You walked in on her eating.