Jaques added two goals in two minutes, firstly from a penalty corner and then a field goal.
Robinson scored her second just before the quarter break, giving Midlands an intimidating 4-0 lead.
Northland came out after the break and showed a lot more tenacity on defence. They almost held Midlands out for the quarter but Lauren Turner nabbed a goal right before the end of the first half.
Jaques completed her hat-trick in the 35th minute with another field goal, giving Midlands a 6-0 lead going into the final quarter.
Natasha Fitzsimmons added a seventh while Robinson closed out the match with her third goal.
Northland sit in fifth after the penultimate round, while Midlands have a chance of making the final.
In the men's competition, Northland scored their first goal of the tournament but were blown away by a superior Midlands team.
Midlands started fast with a fourth-minute goal to Aidan Sarikaya but Northland fought back with good attack and solid defence.
Midlands extended their lead in the 17th minute through Leo Mitai-Wells.
Northland struck back five minutes later, with Hamish McKechnie scoring Northland's opener.
Zac Woods immediately nullified McKechnie's goal with a strike of his own.
Mitai-Woods scored soon after and once Adriaan Stolk nailed a penalty corner, Midlands were carrying a 5-1 lead into halftime.
Northland defended admirably throughout the third quarter and kept Midlands scoreless, but were unable to make any headway on the lead.
Midlands ended strongly, scoring goals through Gabriel Ho-Garcia, Joseph Lyons and Sarikaya to give them an 8-1 victory.
Northland remain firmly entrenched at the bottom of the ladder. Midlands could qualify for the final with a win in the final round.
