My father-in law passed in 2017, 2 of his stocks are still ONLY in his name (not joint). Does my mother-in-law claim that as income (dividends) under her name for 2018?

[MichaelL1]

If the Estate is closed you mother in law should report the income on her return.

She should also notify the firm holding the stock to get it in her name for next years return.