Mother-in-law sold her primary residence. Does she have to fill out taxes??

[Joel Owens]

Mother-in-law is 71.

She sold her primary residence last year she has lived in forever. Owes no capital gains tax as the amount she received was under the 250,000 exclusion.

She hasn't been required to file taxes for years and years as she is retired and only gets a very small social security check each month that falls under the annual income minimums.

She lives in an apartment basement now in my brother-in-law's house.

Does she need to report she sold her house to the IRS for taxes even though no taxes are owed and she hasn't filed in years?? I didn't know if even though no taxes owed there was still a reporting form required to the IRS.