TL;DR: Alice & Bob work as contractors for a Canadian company, in Canada. Alice is underpaid, Bob is/was overpaid. How can Bob (legally) compensate Alice for her work?
I am working as a lead software dev in a small team for a large Canadian corporation. One of my teammates, call her Alice, was interviewed and hired 3 months ago as a junior developer at a rate of 35$/h. Over the last few months, she has proven to be far more capable than we expected, and we (team members and manager) estimate that she should instead be at the 50-55$/h paygrade. Her contributions are essential to our team's continuing existence and the success of its projects.
The problem is that corporate policy prevents giving raises within the first 6 months. I've also been experiencing personal issues which lowered my ability to work during the past few weeks, but I've continued to be paid normally (at 65$/h), both to avoid HR issues and because "everyone has their bad month" (in my manager's words).
From a legal standpoint, we are contractors: we are both sole proprietors of our respective sole proprietorships, and we are selling our services to the large corporation.
I would like to financially compensate Alice for her work. What's the least-annoying legal way of accomplishing this? Can I ask her to write me invoices for programming work to make up for the difference until her raise comes through in three months?