Can I claim my mother-in-law as a dependent?

[jrwebb31]

She lived with us for several years.  She had a low paying job but did not pay anything for rent, utilities, etc.  Then last year she became ill and only worked 2 week and passed away in September.

[Marketstar]

You may be able to claim your mother in law as a Qualifying Relative dependent (even though she passed away in 2016) if:

• You provided more than half of her support in 2016
• She earned less than $4,050 in gross taxable income. (Social Security income generally doesn’t count here.)
•  She lives with you 365 days in the year or is related to you.
•  She isn’t a dependent on someone else’s tax return.
• She isn’t filing a tax return with a spouse (married filing jointly).
• She was a U.S. citizen, resident alien, national, or a Canadian or Mexican resident

You can’t claim a dependent if you are a dependent on someone else’s taxes

See Rules For Claiming Dependents