Visitor Visa - duration before re-entry

[dontad]

Hi

My parents are visiting USA on multiple-entry visitor visa.
They came to USA in Oct-2023.
They are planning to travel to India in end-Jan-2024 and return back to USA in 2 weeks.

Question:
(1) Is it ok to return back to USA in about 2 weeks time?
(2) Is there a duration that needs to be spend outside the country before returning back on visitor visa?

Thank you