Final answer:
The blank in the sentence can be filled with words like 'ambivalent', 'resistant', or 'averse' to describe Lily's attitude towards helping to take care of Gabriel, as she seems to be reluctant and burdened by the obligation.
Step-by-step explanation:
The sentence "Lily was constantly _______ towards the idea of helping to take care of Gabriel" requires filling in the blank with a word that appropriately describes Lily's attitude or behavior towards the responsibility of caring for Gabriel. Given the texts provided, the feeling seems to be a mixture of reluctance and the burden of obligation. Therefore, suitable words to complete the sentence might be 'ambivalent', 'resistant', or 'averse'. These words suggest that Lily was not fully comfortable or in favor of the idea of helping to take care of Gabriel.