Answer :

Dr. Wilson

She gets 1 partridge in a pear tree on each of the 12 days. 1 x 12 12

She gets 10 lords a-leaping on the last 3 days. 10 x 3 30

She gets 11 pipers piping on the last 2 days. 11 x 2 22

She gets 12 drummers drumming on the last day. 12 x 1 12

Total  364