How has your mother's health have been since then?
その後、お母様の具合はいかがですか?
- How has your mother's health have been since then?
- How has your mother been feeling since then?
他:
- Is your mother feeling better?
- How is your mother's condition now?
- Is your mother okay?
If it's ok to ask, how is your mother's condition?
ご質問ありがとうございます。
このシチュエーションで、先生のお母さんの調子を聞きたいなら、英語で「If it's ok to ask, how is your mother's condition?」と言えます。
最初の「If it's ok to ask...」は少し個人の質問をするとき、相手に大丈夫かどうか確認するため、このような表現を使います。
ご参考になれば幸いです。