She isn't going to be able to attend classes

[Anna232]

Are both versions of the same sentence correct?

1.a My daughter isn't going to be able to be present on the lessons due to our planned vacation.
5.b She isn't going to be able to go to classes due to our planned vacation.

Is " to be present on the lessons" correct?

 

[Tarheel]

Is " to be present on the lessons" correct?

No, I don't think so. Also, I don't know why you don't use what you have in the title. In my humble opinion that's the best choice.

 

[emsr2d2]

Are both versions of the same following sentence correct?

1a. My daughter isn't going to be able to be present on the lessons due to our planned vacation.
5b. She isn't going to be able to go to classes due to our planned vacation.

Is "to be present on the lessons" correct?

If this is part of the "letter to a teacher" topic, I find them both unnatural. I'd say "My daughter will be absent from class/school on [dates] because we will be on vacation".