The word 'mother' should be capitalised in place of someone's name. However, since you have already mentioned that she is called 'Sonya', the word 'mother' should not be capitalised.
Answer: Or
Explanation: I Got It Right On Odyssey
(p.126, The African American and the Settling of the West, Sarah Nichols and Marie Hernandez, ed.Aaron Wilds.)
The letter following the quotation needs to be capital. This is because what the person said is also a sentence.
Example: As Mark was walking he said, "This is a beautiful day!"
Happy to help!
