Get two body shots than....sometimes it isn't even about killing blows as her if you can zone out an area due to widow threat you funnel.enemies into a team fight on your teams ground..... also just get gud duh
Have a list.
1, 144 hz Monitor does help. (Check it in Youtube)
2, try different sensitivities on scope/off scope
3, check if there is headshot n sniper match in arcade.
4, find good sniper spots
Widowmaker isn’t about headshots only. You can add a big zone threat level to an enemy team and keep them busy on chokes. And if they have to change to ape and flankers to get you, well more time for your team and less attention on your healer. + when you change constantly positions with her it’s hard for them to adapt.
When you are not total bad you usually have at least silver in Dmg and kills (mostly I have golds) and as a good Widowmaker i have often enough gold in Objective time(needs to be good at flick and jumpshots).
My 50 cents on topic. But works, last 2 Seasons I had 69% and 64% winrate with her.