Can you please check the grammar in the following sentences, please?

Thank you very much in advance.

1)If I hadn’t missed it, I would have arrived on time at the theatre and I could have seen Murphy’s performance.
2) I don’t feel well and I’d prefer to go to bed early.
3)Mrs. Ryan would prefer the children to stop playing (or would rather they stopped playing) because they are sweating.
4) She told me that her father was angry with her because she hadn’t passed her biology exam.
5)Sandra wishes her boyfriend hadn’t bought her a golden ring for her birthday.
6) It is high time you tidied up your room.
7) Melanie said she wouldn’t tell anything to her boyfriend because she wanted to make him a surprise.
8) If my friends had had a map, they wouldn’t have got lost. I’m used to getting up early/I was used to sleeping after lunch.
9) She begged them not to do anything dangerous.
10) She suggested I go (or I should go) to bed early.
11) I just wanted to remind you that you will be having lesson in (or with?) the third class on Wednesday.
12) She refused/offered to help us.
She suggested/recommended/proposed/
admitted/denied going to the party

3)Mrs. Ryan would prefer that the children stop playing because they are sweating.

In #7, I'd use "give" rather than "make."

In #10, either phrasing will do.

In #11, the preposition you choose changes the meaning slightly. What is meant by this?

All the others are fine.

1) The grammar in sentence 1 is correct. It is a conditional sentence using the third conditional form "If I hadn't missed it, I would have arrived on time at the theatre and I could have seen Murphy's performance."

2) The grammar in sentence 2 is correct. It is a simple sentence expressing a preference: "I don't feel well and I'd prefer to go to bed early."

3) The grammar in sentence 3 is correct. It is a sentence using the modal verb "would prefer" to express preference. It can be written in two ways: "Mrs. Ryan would prefer the children to stop playing" or "Mrs. Ryan would rather they stopped playing because they are sweating."

4) The grammar in sentence 4 is correct. It is a reported speech sentence: "She told me that her father was angry with her because she hadn't passed her biology exam."

5) The grammar in sentence 5 is correct. It is a sentence using the past subjunctive form: "Sandra wishes her boyfriend hadn't bought her a golden ring for her birthday."

6) The grammar in sentence 6 is correct. It is a sentence using the phrase "It is high time" followed by a verb in the past simple tense: "It is high time you tidied up your room."

7) The grammar in sentence 7 is correct. It is a sentence using reported speech: "Melanie said she wouldn't tell anything to her boyfriend because she wanted to make him a surprise."

8) The grammar in sentence 8 is correct. It is a conditional sentence using the third conditional form: "If my friends had had a map, they wouldn’t have got lost." The second part of the sentence seems to be unrelated, as it is a different grammatical structure. It should be a separate sentence.

9) The grammar in sentence 9 is correct. It is a sentence using the verb "begged" followed by the pronoun "them" and a negative sentence: "She begged them not to do anything dangerous."

10) The grammar in sentence 10 is correct. It is a sentence using the verb "suggested" followed by the pronoun "I" and the base form of the verb: "She suggested I go (or I should go) to bed early."

11) The grammar in sentence 11 is correct. It is a sentence using the verb "remind" followed by the pronoun "you" and a prepositional phrase: "I just wanted to remind you that you will be having a lesson in the third class on Wednesday." The preposition "in" is correct in this context.

12) The grammar in sentence 12 seems incomplete or incorrect. Please provide more information or clarify the sentence to allow for accurate grammar assessment.