Parent as a dependent

My 91 year old mother lives with us and has for several years. Up to 2019 we have filed tax returns for her and she always gets a refund if she had any Federal withholding. Her sole income is SS and interest/dividends and a required RMD from her IRA. Not counting SS her income for 2019 was under $4300. Can we claim her as a dependent on our 2020 taxes we are filing? Would that trigger an IRS audit? Are there any other ramifications to declaring her as a dependent we are thinking about. We supply all her food and clothing. She pays her own medical costs.

Thanks