"How is your mother doing?"
How do I say "How is your mother doing?". I know her mother has been ill and would like to ask her in español.
4 Answers
¿Cómo sigue tu madre? is my option.
Be prepared for a reply such as
Ahi anda - Oh, so-so
¿Cómo está su madre? - How is your mother?
addendum:
When we use English, and we ask - How is your mother doing?...What we are attempting to learn is: (how she is...with regard to her physical, mental, etc. state of condition. Spanish uses the verb (estar) for "place, condition". While "place, condition" may not totally encapsulate the meaning of this verb, it does however provide a broader understanding of its usage.
I would like to thank my friend Mariana for her keen insight. You also need to read the information she provided for you. 
¿Cómo ha estado su madre? – How has your mother been?
You have a wonderful day, and please continue using this sight. Viejito
¿Cómo se va tu mamá?
How is your mum?
Viejito is correct. You can say this two ways depending on your relationship with the person with whom you are speaking--
¿Cómo está su madre? - How is your mother? (formal usted speech if you are speaking to a boss, an acquaintance, elderly person, etc.).
¿Cómo está tu madre? - How is your mother? (informal speech for friends, peers, and children).
