Final answer:
Keane's desire to change Valenzuela's name was motivated by protection against racism
Step-by-step explanation:
Keane's desire to change Valenzuela's name was probably motivated more by protection against racism than commercial gain. Based on the provided information, several letters referred to the purchase of a house and the need to keep the Shanly name out of it due to a fear that the heir to the house would inflate the value if she was aware of the prospective purchaser's name. This suggests that Keane wanted to change Valenzuela's name to protect her from potential racism and discrimination, rather than for commercial gain.