Natasha Romanoff was a young Soviet citizen when her government chose to train her in espionage. During her time in the infamous Red Room Academy, she became the master spy known as the Black Widow.Marvel Source
Early in her career, the Black Widow clashed with Iron Man, but her loyalty to her country waned and eventually she switched sides and joined S.H.I.E.L.D. She later joined the Avengers, and has served with distinction on that team many times.
when playing around with BW on testcenter I came up with this build.
It is working very good for me, hope that you will like it too.
This build relies on her range skill tree.
You won't need any drones on her, I didn't like em that much at all (never got to the 27+ in drones before they got fixed).
With this build you deal enough ranged damage.
Evasive shot fits perfectly into this build when fighting terminal bosses.
With the maxed Master of Munitions you hardly run out of spirit and you will also have the dodge combo there.
You will see a lot of crits and also some red crits which means that you landed a brutal strike.
Widow's Kiss is a one point wonder, try to keep that up on villains and harder mobs to reduce their damage.
I'd spend one of the additional power points from the quest line on Escape Roll to get faster through the terminals.
LMB: Snap Shot (used when out of spirit)
RMB: Stinging Barrage (your default trash pack and boss killer)
A: Evasive Shot
S: Widow's Kiss
D: Escape Roll
Elektra medallion is better than Bullseye with this build since BW relies strongly on dodge to avoid damage and it will also guarantee you critical hits for 2 seconds with FFoF.
For costume affixes you want to go with defensive affixes and look out for dodge.