thank you for your query.
your mother can take a single dose of 600mg.
or else you can also start with of 200 mg mifepristone orally followed 48 h later by 0.4 mg misoprostol
orally for menstrual regulation
either of these are effective.
but kindly consult your OB/GYN before taking any tablets due to their side effects.
wishing you good health