Chasing 261 for victory, Illingworth made four as his team lost by 40 runs.
She was run out as Australia lost by 56 runs.
Grace got heavily criticised as England lost by 72 runs.
Davidson managed only one as Australia lost by 222 runs.
She made six in the fourth match, her first innings at international level as Australia lost by 59 runs.
Armstrong scored 1 run and took 2/22 with the ball, as the Bahamas lost by 57 runs.
She then top-scored with 56 as Australia lost by seven runs.
In the second innings, he took 1/79 and Australia lost by 170 runs.
The series was lost in the third Test as India lost by 185 runs.
He was the last man out as Devon lost by 180 runs.