The condition of the will [in the form of a codicil] is that after he spends his $1,000, he has to give an account -in writing- of how he spent his money to the lawyer Tolman, who has been appointed for this purpose by old Gillian.
Tolman informs him that Miss Hayden received $10 and a sealing ring, the same as the butler and housekeeper.
[1] One interpretation posits that Young Gillian had a change of heart and character (from being a wastrel and spendthrift to a person of substance) when he sought advice from a blind man selling pencils on the corner.
This could explain Gillian's light-hearted exit from the lawyer Toler's office after tearing up his accounting of how he spent the initial $1,000.
Arguably, this story turns The Gift of the Magi on its head as both Gillian and Miss Hayden are benefitted without any real loss to either.