If I understand correctly, what confuses you is the use of past perfect (had gotten/had received) instead of past simple (got/received).
The typical use of past perfect is a past action completed before another past action. You receiving the email was before her making sure of it. That is why if making sure of it is in the past, receiving it should be even earlier in the past, which means past perfect.
So yes, her sentence is grammatically the best choice here. Yours would be a very commonly used one, which does not follow the correct grammar rules. She could have also said "I just want to be sure that you have got it." (Which is a version of what she actually used, only avoiding the past tense.)
Whether is not a question word, although it looks like one.
Question words beginning with wh are the following:
- what
- which
- where
- who
- whose
- when
- why
The rule for making questions using question words is fairly simple:
Question word + auxiliary + subject + infinite or, "QUASI" is a useful acronym. (It is not infallible but it works most of the time)
1) Which colour did she choose to make it? Blue or green? (if there is a limited choice)
2) What colours did she use? (a wider choice of colours is inferred here)
3) Who made it? Did you? OR "Was it me or you?" (in this case, who is the subject of the question and does not require an auxiliary)
You can omit the wh question word and ask a yes/no type question.
Auxiliary + subject + infinite
- "Did you use blue or green?" asked Maria.
- Maria asked, "Did you make it?"
If you wanted to use whether you have to rephrase your sentence. Note that the following are not questions. There is no question mark at the end.
- Maria asked whether she used blue or green.
- Maria asked whether [name] made it or not.
If you really need to make questions with whether then the following is acceptable
- Do you know whether she used blue or green to make her scarf (it)?
- Did you find out whether it was me or her who made it?
Best Answer
"How old is your unborn baby?" is not grammatically wrong, but is not the way people usually ask the question. We normally count age from birth, not conception -- I presume because we know exactly when a baby is born, but we rarely know for sure when he was conceived -- so to be consistent an unborn baby's age would be a negative number!
The common way to ask the question is, "How far along are you?" or "How far along is your baby?" A woman will often say, "I am three months pregnant". But then we also say "the baby is three months old" or whatever number.
Doctors will say that a baby is "three months gestation". Sometimes they talk about age since the mother's last menstrual period, as in, "the baby is three months LMP". LMP is also a date that the mother is likely to know. It's usually a couple of weeks before conception, but close enough. Medical researchers talk about "embryonic age", which may be abbreviated to simply "age". But these terms are rarely used in casual conversation.