McDonald, at No.1 in the team, enjoyed one of her most successful interprovincials.
She ended the week with a record of five wins and two defeats.
Player of the tournament Vivian Lu of Auckland won six and lost two.
McDonald and No.4 Fiona Ellis provided the wins in HBPB's positional playoff.
It was the second time that week McDonald had beaten Northland No.1 Shardae Bulkeley.
HBPB had 3½ team wins over the week. They had a half against Northland to start the week, and beat Taranaki 4-1, Waikato 3-2 and Tasman 4-1.
Auckland won their fifth consecutive women's national interprovincial crown. They beat Canterbury 4½-½ in a one-sided final on Saturday afternoon.
The Aucklanders finished with a perfect team record of wins over the week.