Final answer:
In the context of 'Jane Eyre', 'doat' suggests a deep affection, hence 'cherish' is the meaning most fitting the usage in the excerpt.
Step-by-step explanation:
In the context of the quoted excerpt from Jane Eyre, the word doat most likely means cherish. The use of 'doated' in the sentence suggests a deep affection or fondness for the 'little toy', to the extent of half-believing it to be alive and capable of sensation. This conveys a sense of endearment and emotional attachment, making 'cherish' the correct meaning of doat among the provided options.