Adding a field to a Parent record that would show the information in a field from the most recent child record.

in my app I have a Loans table and the client wants to be able to add new Loan Balances to the loan with date, balance, & notes fields. The best way I know to do this would be to create a Balances table related to the Loans table so that each Loan could have many Balances. What I am wondering is if there is a way to set up a Balance field on on the parent Loans table that will always display the most recent balance entered into the Balance table?

Short of that i know I can show a record list of the balances on the interface with add buttons so they can add new balances that way, but they also want to be able to report of the current balances and to use the child table would mean having to pull several pieces of information from the parent Loan table down to the child Balance table which I think would be much more difficult to do.