@Unime
Although she is a robot must still power herself, just as a smartphone needs to recharge its battery or a gasoline car.
She is probably built so that the food she ingests becomes energy to feed her mechanisms, just like us living beings.
The story is Japanese foodie science fantasy, so being troubled about explanations may be redundant. Still, a simple one is available. The objective of her creator was to make something very close to H. sapiens. So, absorbing material and energy as she does suits her function.
That's the general expectation. The explanation will probably be that she had to punt to transferring her consciousness into the dog robot, when she found herself collapsing sooner than she'd hoped or somesuch.
A problem with translating Japanese into English is that many things that are not gendered in Japanese are gendered in English. Unfortunately, most translators just use the male gender. So a lady is called a “lord”, a duchess a “duke”, a mistress a “master”, and so forth. This robot is seeking her mistress.
@Oeconomist that is indeed correct, Japanese tends to leave out gender which makes it hard to translate into English sometimes. The reason why I chose master as opposed to mistress or another word is because to me, master is gender neutral. Also, mistress feels dated and I don't see it used in general conversation much anymore. In the end, I had to make a decision and to use master is the one I ended up choosing. I hope that does not diminish your reading experience.