Email preferences: Board comms vs ticketing

Hello friends,

This is a question about email preferences in a Tessitura/TNEW org that uses Mailchimp. 

Carol Brady is on our board and is a large donors. She has two accounts in Tessitura- one is the gmail account that is associated with the record we've had for her for ages. One is an account she just recently created so that she could access some free digital content, and this one uses a yahoo email. Thus, two Tessitura records/accounts were created. Then, she hopped into her gmail account and unsubscribed her gmail address. 

We called Carol to see what her preference was. She wants ticketing and promotional emails to go to yahoo. She wants other personal communications (like notice of a board meeting or some personal solicitations) to go to gmail. What is the best way to handle this? 

My first reaction is to delete the duplicate with the yahoo address but keep it as the primary email in her longstanding account. But what to do with that gmail address which she prefers for personal communications with a Devo manager, board meeting emails, and other stuff?