How can I file taxes if I am a grandparent that was paid to watch my granddaughter? I babysat in her parents home and they paid me 1,000 per month in cash.

You would file a Sch C reporting the cash income and takes any expenses you incurred in earning the income.

Getting paid by cash or check or with or without a 1099 does not matter, it is still income that needs to be reported.

Please see below for details on a Sch C. 

https://ttlc.intuit.com/replies/3302122