Your client Amy, a 40-year-old accountant from Ontario, works for ABC Inc. Her annual income from ABC is $60,000. During tax season, Amy prepares tax returns for her friends and earns an extra $2,000.

Each year, Amy contributes $4,000 to an RRSP. Amy 2-year-old son Oscar, is in day care 4 days per week, costing $300 per month.

On Fridays, her mother looks after Oscar at no charge.

What is Amy's marginal tax rate? If she received another $100 of income, how much additional tax would she pay?