Dealing with Duplicate Info Multiple Records

Our website collects client submissions yearly from parents about their children using Ninja Forms. We are hoping to use Mailpoet to send newsletters back to the parent’s email address from time to time.

– Parents can have more than one child entered, but would use the same email address for themselves.
– Parents can sign up their children multiple years.
– Our newsletters to the parents use fields to reference their name and the names of their children.

When importing the submissions from Ninja Forms (via csv), MailPoet truncates the list to remove duplicates (it somehow determines) and the information about the child/sibling is lost. And if the parent/child was registered in a previous year, it doesn’t import them either.

Please advise on keeping records where some of the information may exist in another record.