Before translation: I'm guessing she's eating the human's chocolate because she didn't get any?

Technically true, but girls don't normally get chocolate for Valentine's Day in Japan. That comes a month later on White Day. She is jealous and eating it in any case though.

Shinjidude said:

She is jealous and eating it in any case though.

She's nomming the choco that hooman got from their significant other after it was accidentally left unattended.

I think cockroach-chan deserves some chocolate anyway. She has been with the human since a long time, and she was even there for them when the human was having a hard time.