"太姥姥" 是指太太的母亲，在英语中可以称作 "mother-in-law"。您可以说 "my mother-in-law" 或 "my wife's mother"。
例句：
My mother-in-law is visiting us this weekend.
I'm going to visit my wife's mother tomorrow.
例句：
My mother-in-law is visiting us this weekend.
I'm going to visit my wife's mother tomorrow.