Taking the wife to SYD in April for 10th Anniversary.

(FSD-DEN-LAX-SYD and same back) booked H class (am 1k, she has no status) used 4 GPU's (2 for her 2 for me) and the domestic portions have cleared, just waiting on the LAX-SYD and the SYD-LAX portion.

Now the question if I clear and she does not can we swap seats mid flight to take turns sleeping? Will UA allow that?

Thanks for the help in advance.