Liverpool were constantly sub-par in the final third throughout the game and failed to find the end product once they got the ball towards good areas.
To their credit, Charlton managed the game well and pressed to keep Liverpool out, but the visitors, who created 2.34 expected goals in normal time, should really have scored.
Mia Enderby came close to breaking the deadlock early on but her close-range effort was palmed over by Whitehouse.
That was one of just two shots on target for Liverpool in normal time, the second being a tame late Martha Thomas effort.
Gareth Taylor’s side also had one disallowed when the offside flag was raised after Beata Olsson sent a backheeled effort past Whitehouse following a Martha Thomas flick.
While Charlton started well as former Liverpool forward Amalie Thestrup caused a few issues, they soon unsurprisingly retreated to a defensive game and managed just one touch in the visitors’ box in the second half.
Thomas sent a powerful strike past Whitehouse from a corner in the first half of extra time, but it was ruled out as she handled the ball when she initially controlled it.
This was a mostly drab affair as neither side produced anywhere near the levels of quality required in the final third, but it proved that Charlton – who are fighting for promotion to the top flight – can definitely compete with Women’s Super League opposition.
Shaw’s late winner means Liverpool have reached the semi-finals for the second season in a row. They lost 2-1 to Chelsea last year.
