do one's best
• do all one can.
• "Ruth did her best to reassure her"
Similar:
do one's utmost,
try one's hardest,
try as hard as one can,
make every effort,
spare no effort,
do all one can,
give one's all,
be at pains,
bend/fall/lean over backwards,
do one's damnedest,
go all out,
pull out all the stops,
bust a gut,
break one's neck,
move heaven and earth,
do one's darnedest/durnedest,
go for the doctor,
