Questions & Answers about tā jīntiān yě méi lái shàngkè.
她 means she / her, while 他 means he / him.
In spoken Mandarin, 她 and 他 are both pronounced tā, so you can only tell them apart in writing. This is very common for beginners to notice because English clearly distinguishes he and she in speech, but Mandarin usually does not.
In Mandarin, time words often go after the subject and before the verb:
她 今天 也 没 来 上课。
She today also did not come to class.
This is a very normal word order in Chinese. A common pattern is:
Subject + Time + Adverb + Verb
You can also sometimes put the time word at the very beginning for emphasis:
今天她也没来上课。
That is also natural.
也 means also or too.
It shows that this situation is true in addition to something else already known from context. For example, maybe someone else did not come to class, and now you are saying that she didn’t come either.
So 也 often depends on context. By itself, it suggests in addition to someone/something else.