Not good enough.
Set crit damage to x3.
Take her primary max damage from 120 down to 60, but buff her refire rate with a solid delay and remove the charge mechanic completely.
Buff her mine into a solid burst damage/escape mechanic with a medium-short range and single target.
Buff her SMG so that close range is no longer her only theoretical weakness.
During her ultimate she gets back her one-shot kills on head-shot. She gets back her charge mechanic and max damage goes up from 60 to 100, preserving 2 bodyshot kills on 200 health targets and 300 damage headshots.
Buff her ult duration from 20 seconds to 30 and let her build up ult charge during her ult like Ashe. At 1800 charge, if you can headshot the entire enemy team, you’ll have back-to-back ults which marks the best theoretical outcome of widowmaker gameplay and her now very solid skill ceiling.
Balance her performance going forward on her non-sniping abilities. Never, ever make her a better sniper in the future, and use her as a measure of how powerful future sniper heroes can ever be.