The prepositions of and about add some indirection to the sentence. For example:
I know him
I know about him
I don't know about him
I know of him
The first means that you know him personally: the second means that you have information or experience of him. The third sentence could either mean that you don't have information about him, or that you do have information and it's not very favourable. The final sentence means that you have heard about him (you know that he exists) but you don't know him personally and don't have any information about him.
Looking at the sentences 1 and 2:
1) I don't know about how you took care of her.
2) I don't know how you took care of her.
The first sentence suggests that you don't have any information about how you took care of her: this might be used to indicate that the speaker doesn't know whether you did the job well or not.
In the second sentence, how is ambiguous: it could relate to what care was given (what specifically was done), or to how it was possible for you to give care to her (what obstacles were overcome).
The latter might be the case if both speaker and listener know that the person whom the listener took care of has in the past been unkind to the listener. For example, if she is the listener's mother, and she had an argument with the listener five years ago and hasn't spoken to her since.
For sentences 3 and 4,
good is often used as an adverb in American English, but in Brtish English, we think that
good is an adjective and
well is the corresponding adverb. For avoidance of doubt (as the lawyers say), I have replaced
good by
well. The preposition
in makes sense if
party is a political party. If you want to talk about a social event, you would have to use the preposition
at.
3) I am thinking of how well he will perform in the party.
4) I am thinking how well he will perform in the party.
Sentence 3 indicates that the speaker is in the process of assembling information about how well he will perform, and has not yet made their mind up.
In sentence 4, the speaker is stating an opinion, and almost-fact, about
how well he will perform.
Best Answer
The grammar is just SVC [There] (a dummy subject), [is] (verb), [no stopping her] (noun phrase complement to the subject, a gerund with its object (stopping her))
Compare "There is no water". Or "There is smoking allowed".
As for meaning, it can be glossed as "She can't be stopped".
As for "There is nothing to stop her". That doesn't mean "She can't be stopped". It means "there are no obstacles". It is also used rather differently: