Back door Roth = putting more than 7000 a year to ROTH IRA = converting 401K to ROTH IRA through traditional IRA rollover. They are the same thing.
401K to ROTH IRA conversion is worth it if there are growth in ROTH IRA because the growth in ROTH is tax free. But if she just want to put her money in cash or low growth investment, maybe it's not worth to convert. Just take the RMD maybe okay.