If you performed the services in HER home, she MUST send you a Form W-2 since you were a household employee. If you have not received it by Feb 15th, call the IRS and file a missing W-2 complaint. The will assist you in getting your W-2.
If she thinks that she can fob off her share of the FICA tax liability on you by giving you a Form 1099 (which would never be appropriate even if you did the work in your own home since it's not a business service) show her IRS Pub 926 url_not_allowed.irs.gov/pub/irs-pdf/p926.pdf and tell her to get off of the stick and get your W-2 to you ASAP.
If you performed the service in YOUR home than you are a self-employed baby sitter or daycare provider and you use your records to prepare your return. She would not provide you with ANY documentation, though she may request your SSN if she will be claiming the Child & Dependent Care Credit. See IRS Pub 587 url_not_allowed.irs.gov/pub/irs-pdf/p587.pdf if that's the case.