Some employers have waived some open enrollment deadlines for applying for a Dependent Care Inflexible Savings Account (a "DC FSA"). This is implemented as a deduction from your income, that can be spent using pre-tax dollars. For 2020 and 2021 the limit is $5000.
For more see https://www.investopedia.com/articles/pf/09/dependent-care-fsa.asp
If you still can, get on board for 2021, however keep in mind unspent dollars get donated to your company.
Look into the "Child and dependent care credit".
Note that age limits are waived, depending on the disability of the child.
And there are phaseouts depending on your income.
And note you can't stack these two credits quite as nicely as you might like.
Finally consider the "unreimbursed medical expense" deduction, available for expenses that exceed 7.5% of your income. Generally, deductible medical expenses must be required by a doctor in writing, though you're probably fine getting the doctor's note now under the circumstances.
Congratulations you're also now an employer and may have a "Zoë Baird Problem" depending on how long this has gone on. You are required to file forms 1099-ENT to report the babysitter's income. Watch out that deadline is February 1st 2021.