You have to pay tax on the income one way or another. If you are a household worker with an employee agreement, she would have to issue you a Form W-2.
Generally, for 2020 an employer needs to pay Social Security and Medicare taxes for “cash wages” of $2200 or more paid to any one employee. Cash wages refer to checks, money orders and the like. They don’t include “the value of food, lodging, clothing, transit passes and other noncash items you give your household employee.” But cash given to an employee in place of those items counts as cash wage.
If you can control how things are done, you are a contractor who receives a 1099-NEC. Even of you do not receive one, you are liable for SE taxes on any cash payment over $400.
