I wish I could let mother/Mother know, as I know she will/would be worried.
1. Should 'mother' be capitalised?
2. is a comma needed after 'know', which is followed by 'as'?
3. Should it be 'will' or 'would'?
Many thanks.
1. Capitalize it. You are using "Mother" as her name, hence it should be capitalized. You could substitute her actual name (like "Elaine") into the sentence. If you said "my mother," you would not capitalize it.
2. I would use a comma
3. I would use "would."
"I wish I could let Mother know, as I know she will be worried." This is correct. If you want to use "would", you could write it like this:"I wish I could let Mother know, as I know she would be worried if I didn't."