AOS Application - Priority Date not current

[immihelp]

My sister is a nurse and has an approved imigrant visa petition under the EB3 category with a priority date of August 31, 2006. as we all know her priority date is not current as of this time. she is planning to come here in US as a visitor ( she already has the visitor's visa) this coming summer. My question is will she be able to apply for adjustment of status while she is here in US as a visitor? i have read that in order to file for AOS, priority date needs to be current, is this true? is she is eligible to apply for AOS, does that mean she can legally stay in US as long as AOS is filed/applied? will she be able to work legally under the AOS status?

Thank you for your help!

[immihelp]

She can apply for AOS only if priority date is current and she is in US at that time. She can also apply for EAD and work at that time.